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<h1><a href="spanner_v1.html">Cloud Spanner API</a> . <a href="spanner_v1.projects.html">projects</a> . <a href="spanner_v1.projects.instances.html">instances</a> . <a href="spanner_v1.projects.instances.databases.html">databases</a> . <a href="spanner_v1.projects.instances.databases.sessions.html">sessions</a></h1>
<h2>Instance Methods</h2>
<p class="toc_element">
  <code><a href="#adaptMessage">adaptMessage(name, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Handles a single message from the client and returns the result as a stream. The server will interpret the message frame and respond with message frames to the client.</p>
<p class="toc_element">
  <code><a href="#adapter">adapter(parent, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Creates a new session to be used for requests made by the adapter. A session identifies a specific incarnation of a database resource and is meant to be reused across many `AdaptMessage` calls.</p>
<p class="toc_element">
  <code><a href="#batchCreate">batchCreate(database, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Creates multiple new sessions. This API can be used to initialize a session cache on the clients. See https://goo.gl/TgSFN2 for best practices on session cache management.</p>
<p class="toc_element">
  <code><a href="#batchWrite">batchWrite(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Batches the supplied mutation groups in a collection of efficient transactions. All mutations in a group are committed atomically. However, mutations across groups can be committed non-atomically in an unspecified order and thus, they must be independent of each other. Partial failure is possible, that is, some groups might have been committed successfully, while some might have failed. The results of individual batches are streamed into the response as the batches are applied. `BatchWrite` requests are not replay protected, meaning that each mutation group can be applied more than once. Replays of non-idempotent mutations can have undesirable effects. For example, replays of an insert mutation can produce an already exists error or if you use generated or commit timestamp-based keys, it can result in additional rows being added to the mutation's table. We recommend structuring your mutation groups to be idempotent to avoid this issue.</p>
<p class="toc_element">
  <code><a href="#beginTransaction">beginTransaction(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Begins a new transaction. This step can often be skipped: Read, ExecuteSql and Commit can begin a new transaction as a side-effect.</p>
<p class="toc_element">
  <code><a href="#close">close()</a></code></p>
<p class="firstline">Close httplib2 connections.</p>
<p class="toc_element">
  <code><a href="#commit">commit(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Commits a transaction. The request includes the mutations to be applied to rows in the database. `Commit` might return an `ABORTED` error. This can occur at any time; commonly, the cause is conflicts with concurrent transactions. However, it can also happen for a variety of other reasons. If `Commit` returns `ABORTED`, the caller should retry the transaction from the beginning, reusing the same session. On very rare occasions, `Commit` might return `UNKNOWN`. This can happen, for example, if the client job experiences a 1+ hour networking failure. At that point, Cloud Spanner has lost track of the transaction outcome and we recommend that you perform another read from the database to see the state of things as they are now.</p>
<p class="toc_element">
  <code><a href="#create">create(database, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Creates a new session. A session can be used to perform transactions that read and/or modify data in a Cloud Spanner database. Sessions are meant to be reused for many consecutive transactions. Sessions can only execute one transaction at a time. To execute multiple concurrent read-write/write-only transactions, create multiple sessions. Note that standalone reads and queries use a transaction internally, and count toward the one transaction limit. Active sessions use additional server resources, so it's a good idea to delete idle and unneeded sessions. Aside from explicit deletes, Cloud Spanner can delete sessions when no operations are sent for more than an hour. If a session is deleted, requests to it return `NOT_FOUND`. Idle sessions can be kept alive by sending a trivial SQL query periodically, for example, `"SELECT 1"`.</p>
<p class="toc_element">
  <code><a href="#delete">delete(name, x__xgafv=None)</a></code></p>
<p class="firstline">Ends a session, releasing server resources associated with it. This asynchronously triggers the cancellation of any operations that are running with this session.</p>
<p class="toc_element">
  <code><a href="#executeBatchDml">executeBatchDml(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Executes a batch of SQL DML statements. This method allows many statements to be run with lower latency than submitting them sequentially with ExecuteSql. Statements are executed in sequential order. A request can succeed even if a statement fails. The ExecuteBatchDmlResponse.status field in the response provides information about the statement that failed. Clients must inspect this field to determine whether an error occurred. Execution stops after the first failed statement; the remaining statements are not executed.</p>
<p class="toc_element">
  <code><a href="#executeSql">executeSql(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Executes an SQL statement, returning all results in a single reply. This method can't be used to return a result set larger than 10 MiB; if the query yields more data than that, the query fails with a `FAILED_PRECONDITION` error. Operations inside read-write transactions might return `ABORTED`. If this occurs, the application should restart the transaction from the beginning. See Transaction for more details. Larger result sets can be fetched in streaming fashion by calling ExecuteStreamingSql instead. The query string can be SQL or [Graph Query Language (GQL)](https://cloud.google.com/spanner/docs/reference/standard-sql/graph-intro).</p>
<p class="toc_element">
  <code><a href="#executeStreamingSql">executeStreamingSql(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Like ExecuteSql, except returns the result set as a stream. Unlike ExecuteSql, there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB. The query string can be SQL or [Graph Query Language (GQL)](https://cloud.google.com/spanner/docs/reference/standard-sql/graph-intro).</p>
<p class="toc_element">
  <code><a href="#get">get(name, x__xgafv=None)</a></code></p>
<p class="firstline">Gets a session. Returns `NOT_FOUND` if the session doesn't exist. This is mainly useful for determining whether a session is still alive.</p>
<p class="toc_element">
  <code><a href="#list">list(database, filter=None, pageSize=None, pageToken=None, x__xgafv=None)</a></code></p>
<p class="firstline">Lists all sessions in a given database.</p>
<p class="toc_element">
  <code><a href="#list_next">list_next()</a></code></p>
<p class="firstline">Retrieves the next page of results.</p>
<p class="toc_element">
  <code><a href="#partitionQuery">partitionQuery(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Creates a set of partition tokens that can be used to execute a query operation in parallel. Each of the returned partition tokens can be used by ExecuteStreamingSql to specify a subset of the query result to read. The same session and read-only transaction must be used by the `PartitionQueryRequest` used to create the partition tokens and the `ExecuteSqlRequests` that use the partition tokens. Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn't possible to resume the query, and the whole operation must be restarted from the beginning.</p>
<p class="toc_element">
  <code><a href="#partitionRead">partitionRead(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Creates a set of partition tokens that can be used to execute a read operation in parallel. Each of the returned partition tokens can be used by StreamingRead to specify a subset of the read result to read. The same session and read-only transaction must be used by the `PartitionReadRequest` used to create the partition tokens and the `ReadRequests` that use the partition tokens. There are no ordering guarantees on rows returned among the returned partition tokens, or even within each individual `StreamingRead` call issued with a `partition_token`. Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn't possible to resume the read, and the whole operation must be restarted from the beginning.</p>
<p class="toc_element">
  <code><a href="#read">read(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Reads rows from the database using key lookups and scans, as a simple key/value style alternative to ExecuteSql. This method can't be used to return a result set larger than 10 MiB; if the read matches more data than that, the read fails with a `FAILED_PRECONDITION` error. Reads inside read-write transactions might return `ABORTED`. If this occurs, the application should restart the transaction from the beginning. See Transaction for more details. Larger result sets can be yielded in streaming fashion by calling StreamingRead instead.</p>
<p class="toc_element">
  <code><a href="#rollback">rollback(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Rolls back a transaction, releasing any locks it holds. It's a good idea to call this for any transaction that includes one or more Read or ExecuteSql requests and ultimately decides not to commit. `Rollback` returns `OK` if it successfully aborts the transaction, the transaction was already aborted, or the transaction isn't found. `Rollback` never returns `ABORTED`.</p>
<p class="toc_element">
  <code><a href="#streamingRead">streamingRead(session, body=None, x__xgafv=None)</a></code></p>
<p class="firstline">Like Read, except returns the result set as a stream. Unlike Read, there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.</p>
<h3>Method Details</h3>
<div class="method">
    <code class="details" id="adaptMessage">adaptMessage(name, body=None, x__xgafv=None)</code>
  <pre>Handles a single message from the client and returns the result as a stream. The server will interpret the message frame and respond with message frames to the client.

Args:
  name: string, Required. The database session in which the adapter request is processed. (required)
  body: object, The request body.
    The object takes the form of:

{ # Message sent by the client to the adapter.
  &quot;attachments&quot;: { # Optional. Opaque request state passed by the client to the server.
    &quot;a_key&quot;: &quot;A String&quot;,
  },
  &quot;payload&quot;: &quot;A String&quot;, # Optional. Uninterpreted bytes from the underlying wire protocol.
  &quot;protocol&quot;: &quot;A String&quot;, # Required. Identifier for the underlying wire protocol.
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # Message sent by the adapter to the client.
  &quot;last&quot;: True or False, # Optional. Indicates whether this is the last AdaptMessageResponse in the stream. This field may be optionally set by the server. Clients should not rely on this field being set in all cases.
  &quot;payload&quot;: &quot;A String&quot;, # Optional. Uninterpreted bytes from the underlying wire protocol.
  &quot;stateUpdates&quot;: { # Optional. Opaque state updates to be applied by the client.
    &quot;a_key&quot;: &quot;A String&quot;,
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="adapter">adapter(parent, body=None, x__xgafv=None)</code>
  <pre>Creates a new session to be used for requests made by the adapter. A session identifies a specific incarnation of a database resource and is meant to be reused across many `AdaptMessage` calls.

Args:
  parent: string, Required. The database in which the new session is created. (required)
  body: object, The request body.
    The object takes the form of:

{ # A session in the Cloud Spanner Adapter API.
  &quot;name&quot;: &quot;A String&quot;, # Identifier. The name of the session. This is always system-assigned.
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A session in the Cloud Spanner Adapter API.
  &quot;name&quot;: &quot;A String&quot;, # Identifier. The name of the session. This is always system-assigned.
}</pre>
</div>

<div class="method">
    <code class="details" id="batchCreate">batchCreate(database, body=None, x__xgafv=None)</code>
  <pre>Creates multiple new sessions. This API can be used to initialize a session cache on the clients. See https://goo.gl/TgSFN2 for best practices on session cache management.

Args:
  database: string, Required. The database in which the new sessions are created. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for BatchCreateSessions.
  &quot;sessionCount&quot;: 42, # Required. The number of sessions to be created in this batch call. The API can return fewer than the requested number of sessions. If a specific number of sessions are desired, the client can make additional calls to `BatchCreateSessions` (adjusting session_count as necessary).
  &quot;sessionTemplate&quot;: { # A session in the Cloud Spanner API. # Parameters to apply to each created session.
    &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
    &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
    &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
    &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
      &quot;a_key&quot;: &quot;A String&quot;,
    },
    &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
    &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for BatchCreateSessions.
  &quot;session&quot;: [ # The freshly created sessions.
    { # A session in the Cloud Spanner API.
      &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
      &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
      &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
      &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
        &quot;a_key&quot;: &quot;A String&quot;,
      },
      &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
      &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
    },
  ],
}</pre>
</div>

<div class="method">
    <code class="details" id="batchWrite">batchWrite(session, body=None, x__xgafv=None)</code>
  <pre>Batches the supplied mutation groups in a collection of efficient transactions. All mutations in a group are committed atomically. However, mutations across groups can be committed non-atomically in an unspecified order and thus, they must be independent of each other. Partial failure is possible, that is, some groups might have been committed successfully, while some might have failed. The results of individual batches are streamed into the response as the batches are applied. `BatchWrite` requests are not replay protected, meaning that each mutation group can be applied more than once. Replays of non-idempotent mutations can have undesirable effects. For example, replays of an insert mutation can produce an already exists error or if you use generated or commit timestamp-based keys, it can result in additional rows being added to the mutation&#x27;s table. We recommend structuring your mutation groups to be idempotent to avoid this issue.

Args:
  session: string, Required. The session in which the batch request is to be run. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for BatchWrite.
  &quot;excludeTxnFromChangeStreams&quot;: True or False, # Optional. If you don&#x27;t set the `exclude_txn_from_change_streams` option or if it&#x27;s set to `false`, then any change streams monitoring columns modified by transactions will capture the updates made within that transaction.
  &quot;mutationGroups&quot;: [ # Required. The groups of mutations to be applied.
    { # A group of mutations to be committed together. Related mutations should be placed in a group. For example, two mutations inserting rows with the same primary key prefix in both parent and child tables are related.
      &quot;mutations&quot;: [ # Required. The mutations in this group.
        { # A modification to one or more Cloud Spanner rows. Mutations can be applied to a Cloud Spanner database by sending them in a Commit call.
          &quot;delete&quot;: { # Arguments to delete operations. # Delete rows from a table. Succeeds whether or not the named rows were present.
            &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. The primary keys of the rows within table to delete. The primary keys must be specified in the order in which they appear in the `PRIMARY KEY()` clause of the table&#x27;s equivalent DDL statement (the DDL statement used to create the table). Delete is idempotent. The transaction will succeed even if some or all rows do not exist.
              &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
              &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
                [
                  &quot;&quot;,
                ],
              ],
              &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
                { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
                  &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
                    &quot;&quot;,
                  ],
                  &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
                    &quot;&quot;,
                  ],
                  &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
                    &quot;&quot;,
                  ],
                  &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
                    &quot;&quot;,
                  ],
                },
              ],
            },
            &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be deleted.
          },
          &quot;insert&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Insert new rows in a table. If any of the rows already exist, the write or transaction fails with error `ALREADY_EXISTS`.
            &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
              &quot;A String&quot;,
            ],
            &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
            &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
              [
                &quot;&quot;,
              ],
            ],
          },
          &quot;insertOrUpdate&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, then its column values are overwritten with the ones provided. Any column values not explicitly written are preserved. When using insert_or_update, just as when using insert, all `NOT NULL` columns in the table must be given a value. This holds true even when the row already exists and will therefore actually be updated.
            &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
              &quot;A String&quot;,
            ],
            &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
            &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
              [
                &quot;&quot;,
              ],
            ],
          },
          &quot;replace&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, it is deleted, and the column values provided are inserted instead. Unlike insert_or_update, this means any values not explicitly written become `NULL`. In an interleaved table, if you create the child table with the `ON DELETE CASCADE` annotation, then replacing a parent row also deletes the child rows. Otherwise, you must delete the child rows before you replace the parent row.
            &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
              &quot;A String&quot;,
            ],
            &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
            &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
              [
                &quot;&quot;,
              ],
            ],
          },
          &quot;update&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Update existing rows in a table. If any of the rows does not already exist, the transaction fails with error `NOT_FOUND`.
            &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
              &quot;A String&quot;,
            ],
            &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
            &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
              [
                &quot;&quot;,
              ],
            ],
          },
        },
      ],
    },
  ],
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The result of applying a batch of mutations.
  &quot;commitTimestamp&quot;: &quot;A String&quot;, # The commit timestamp of the transaction that applied this batch. Present if `status` is `OK`, absent otherwise.
  &quot;indexes&quot;: [ # The mutation groups applied in this batch. The values index into the `mutation_groups` field in the corresponding `BatchWriteRequest`.
    42,
  ],
  &quot;status&quot;: { # The `Status` type defines a logical error model that is suitable for different programming environments, including REST APIs and RPC APIs. It is used by [gRPC](https://github.com/grpc). Each `Status` message contains three pieces of data: error code, error message, and error details. You can find out more about this error model and how to work with it in the [API Design Guide](https://cloud.google.com/apis/design/errors). # An `OK` status indicates success. Any other status indicates a failure.
    &quot;code&quot;: 42, # The status code, which should be an enum value of google.rpc.Code.
    &quot;details&quot;: [ # A list of messages that carry the error details. There is a common set of message types for APIs to use.
      {
        &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
      },
    ],
    &quot;message&quot;: &quot;A String&quot;, # A developer-facing error message, which should be in English. Any user-facing error message should be localized and sent in the google.rpc.Status.details field, or localized by the client.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="beginTransaction">beginTransaction(session, body=None, x__xgafv=None)</code>
  <pre>Begins a new transaction. This step can often be skipped: Read, ExecuteSql and Commit can begin a new transaction as a side-effect.

Args:
  session: string, Required. The session in which the transaction runs. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for BeginTransaction.
  &quot;mutationKey&quot;: { # A modification to one or more Cloud Spanner rows. Mutations can be applied to a Cloud Spanner database by sending them in a Commit call. # Optional. Required for read-write transactions on a multiplexed session that commit mutations but don&#x27;t perform any reads or queries. You must randomly select one of the mutations from the mutation set and send it as a part of this request.
    &quot;delete&quot;: { # Arguments to delete operations. # Delete rows from a table. Succeeds whether or not the named rows were present.
      &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. The primary keys of the rows within table to delete. The primary keys must be specified in the order in which they appear in the `PRIMARY KEY()` clause of the table&#x27;s equivalent DDL statement (the DDL statement used to create the table). Delete is idempotent. The transaction will succeed even if some or all rows do not exist.
        &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
        &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
          [
            &quot;&quot;,
          ],
        ],
        &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
          { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
            &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
              &quot;&quot;,
            ],
            &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
              &quot;&quot;,
            ],
            &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
              &quot;&quot;,
            ],
            &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
              &quot;&quot;,
            ],
          },
        ],
      },
      &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be deleted.
    },
    &quot;insert&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Insert new rows in a table. If any of the rows already exist, the write or transaction fails with error `ALREADY_EXISTS`.
      &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
        &quot;A String&quot;,
      ],
      &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
      &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
        [
          &quot;&quot;,
        ],
      ],
    },
    &quot;insertOrUpdate&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, then its column values are overwritten with the ones provided. Any column values not explicitly written are preserved. When using insert_or_update, just as when using insert, all `NOT NULL` columns in the table must be given a value. This holds true even when the row already exists and will therefore actually be updated.
      &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
        &quot;A String&quot;,
      ],
      &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
      &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
        [
          &quot;&quot;,
        ],
      ],
    },
    &quot;replace&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, it is deleted, and the column values provided are inserted instead. Unlike insert_or_update, this means any values not explicitly written become `NULL`. In an interleaved table, if you create the child table with the `ON DELETE CASCADE` annotation, then replacing a parent row also deletes the child rows. Otherwise, you must delete the child rows before you replace the parent row.
      &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
        &quot;A String&quot;,
      ],
      &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
      &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
        [
          &quot;&quot;,
        ],
      ],
    },
    &quot;update&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Update existing rows in a table. If any of the rows does not already exist, the transaction fails with error `NOT_FOUND`.
      &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
        &quot;A String&quot;,
      ],
      &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
      &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
        [
          &quot;&quot;,
        ],
      ],
    },
  },
  &quot;options&quot;: { # Options to use for transactions. # Required. Options for the new transaction.
    &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
    &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
    &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
    },
    &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
      &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
      &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
      &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
      &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
      &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
      &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
    },
    &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
      &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
      &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
    },
  },
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request. Priority is ignored for this request. Setting the priority in this `request_options` struct doesn&#x27;t do anything. To set the priority for a transaction, set it on the reads and writes that are part of this transaction instead.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A transaction.
  &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
}</pre>
</div>

<div class="method">
    <code class="details" id="close">close()</code>
  <pre>Close httplib2 connections.</pre>
</div>

<div class="method">
    <code class="details" id="commit">commit(session, body=None, x__xgafv=None)</code>
  <pre>Commits a transaction. The request includes the mutations to be applied to rows in the database. `Commit` might return an `ABORTED` error. This can occur at any time; commonly, the cause is conflicts with concurrent transactions. However, it can also happen for a variety of other reasons. If `Commit` returns `ABORTED`, the caller should retry the transaction from the beginning, reusing the same session. On very rare occasions, `Commit` might return `UNKNOWN`. This can happen, for example, if the client job experiences a 1+ hour networking failure. At that point, Cloud Spanner has lost track of the transaction outcome and we recommend that you perform another read from the database to see the state of things as they are now.

Args:
  session: string, Required. The session in which the transaction to be committed is running. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for Commit.
  &quot;maxCommitDelay&quot;: &quot;A String&quot;, # Optional. The amount of latency this request is configured to incur in order to improve throughput. If this field isn&#x27;t set, Spanner assumes requests are relatively latency sensitive and automatically determines an appropriate delay time. You can specify a commit delay value between 0 and 500 ms.
  &quot;mutations&quot;: [ # The mutations to be executed when this transaction commits. All mutations are applied atomically, in the order they appear in this list.
    { # A modification to one or more Cloud Spanner rows. Mutations can be applied to a Cloud Spanner database by sending them in a Commit call.
      &quot;delete&quot;: { # Arguments to delete operations. # Delete rows from a table. Succeeds whether or not the named rows were present.
        &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. The primary keys of the rows within table to delete. The primary keys must be specified in the order in which they appear in the `PRIMARY KEY()` clause of the table&#x27;s equivalent DDL statement (the DDL statement used to create the table). Delete is idempotent. The transaction will succeed even if some or all rows do not exist.
          &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
          &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
            [
              &quot;&quot;,
            ],
          ],
          &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
            { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
              &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
                &quot;&quot;,
              ],
              &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
                &quot;&quot;,
              ],
              &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
                &quot;&quot;,
              ],
              &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
                &quot;&quot;,
              ],
            },
          ],
        },
        &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be deleted.
      },
      &quot;insert&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Insert new rows in a table. If any of the rows already exist, the write or transaction fails with error `ALREADY_EXISTS`.
        &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
          &quot;A String&quot;,
        ],
        &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
        &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
          [
            &quot;&quot;,
          ],
        ],
      },
      &quot;insertOrUpdate&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, then its column values are overwritten with the ones provided. Any column values not explicitly written are preserved. When using insert_or_update, just as when using insert, all `NOT NULL` columns in the table must be given a value. This holds true even when the row already exists and will therefore actually be updated.
        &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
          &quot;A String&quot;,
        ],
        &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
        &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
          [
            &quot;&quot;,
          ],
        ],
      },
      &quot;replace&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Like insert, except that if the row already exists, it is deleted, and the column values provided are inserted instead. Unlike insert_or_update, this means any values not explicitly written become `NULL`. In an interleaved table, if you create the child table with the `ON DELETE CASCADE` annotation, then replacing a parent row also deletes the child rows. Otherwise, you must delete the child rows before you replace the parent row.
        &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
          &quot;A String&quot;,
        ],
        &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
        &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
          [
            &quot;&quot;,
          ],
        ],
      },
      &quot;update&quot;: { # Arguments to insert, update, insert_or_update, and replace operations. # Update existing rows in a table. If any of the rows does not already exist, the transaction fails with error `NOT_FOUND`.
        &quot;columns&quot;: [ # The names of the columns in table to be written. The list of columns must contain enough columns to allow Cloud Spanner to derive values for all primary key columns in the row(s) to be modified.
          &quot;A String&quot;,
        ],
        &quot;table&quot;: &quot;A String&quot;, # Required. The table whose rows will be written.
        &quot;values&quot;: [ # The values to be written. `values` can contain more than one list of values. If it does, then multiple rows are written, one for each entry in `values`. Each list in `values` must have exactly as many entries as there are entries in columns above. Sending multiple lists is equivalent to sending multiple `Mutation`s, each containing one `values` entry and repeating table and columns. Individual values in each list are encoded as described here.
          [
            &quot;&quot;,
          ],
        ],
      },
    },
  ],
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. If the read-write transaction was executed on a multiplexed session, then you must include the precommit token with the highest sequence number received in this transaction attempt. Failing to do so results in a `FailedPrecondition` error.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;returnCommitStats&quot;: True or False, # If `true`, then statistics related to the transaction is included in the CommitResponse. Default value is `false`.
  &quot;singleUseTransaction&quot;: { # Options to use for transactions. # Execute mutations in a temporary transaction. Note that unlike commit of a previously-started transaction, commit with a temporary transaction is non-idempotent. That is, if the `CommitRequest` is sent to Cloud Spanner more than once (for instance, due to retries in the application, or in the transport library), it&#x27;s possible that the mutations are executed more than once. If this is undesirable, use BeginTransaction and Commit instead.
    &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
    &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
    &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
    },
    &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
      &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
      &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
      &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
      &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
      &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
      &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
    },
    &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
      &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
      &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
    },
  },
  &quot;transactionId&quot;: &quot;A String&quot;, # Commit a previously-started transaction.
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for Commit.
  &quot;commitStats&quot;: { # Additional statistics about a commit. # The statistics about this `Commit`. Not returned by default. For more information, see CommitRequest.return_commit_stats.
    &quot;mutationCount&quot;: &quot;A String&quot;, # The total number of mutations for the transaction. Knowing the `mutation_count` value can help you maximize the number of mutations in a transaction and minimize the number of API round trips. You can also monitor this value to prevent transactions from exceeding the system [limit](https://cloud.google.com/spanner/quotas#limits_for_creating_reading_updating_and_deleting_data). If the number of mutations exceeds the limit, the server returns [INVALID_ARGUMENT](https://cloud.google.com/spanner/docs/reference/rest/v1/Code#ENUM_VALUES.INVALID_ARGUMENT).
  },
  &quot;commitTimestamp&quot;: &quot;A String&quot;, # The Cloud Spanner timestamp at which the transaction committed.
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # If specified, transaction has not committed yet. You must retry the commit with the new precommit token.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;snapshotTimestamp&quot;: &quot;A String&quot;, # If `TransactionOptions.isolation_level` is set to `IsolationLevel.REPEATABLE_READ`, then the snapshot timestamp is the timestamp at which all reads in the transaction ran. This timestamp is never returned.
}</pre>
</div>

<div class="method">
    <code class="details" id="create">create(database, body=None, x__xgafv=None)</code>
  <pre>Creates a new session. A session can be used to perform transactions that read and/or modify data in a Cloud Spanner database. Sessions are meant to be reused for many consecutive transactions. Sessions can only execute one transaction at a time. To execute multiple concurrent read-write/write-only transactions, create multiple sessions. Note that standalone reads and queries use a transaction internally, and count toward the one transaction limit. Active sessions use additional server resources, so it&#x27;s a good idea to delete idle and unneeded sessions. Aside from explicit deletes, Cloud Spanner can delete sessions when no operations are sent for more than an hour. If a session is deleted, requests to it return `NOT_FOUND`. Idle sessions can be kept alive by sending a trivial SQL query periodically, for example, `&quot;SELECT 1&quot;`.

Args:
  database: string, Required. The database in which the new session is created. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for CreateSession.
  &quot;session&quot;: { # A session in the Cloud Spanner API. # Required. The session to create.
    &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
    &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
    &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
    &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
      &quot;a_key&quot;: &quot;A String&quot;,
    },
    &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
    &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A session in the Cloud Spanner API.
  &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
  &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
  &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
  &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
    &quot;a_key&quot;: &quot;A String&quot;,
  },
  &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
  &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
}</pre>
</div>

<div class="method">
    <code class="details" id="delete">delete(name, x__xgafv=None)</code>
  <pre>Ends a session, releasing server resources associated with it. This asynchronously triggers the cancellation of any operations that are running with this session.

Args:
  name: string, Required. The name of the session to delete. (required)
  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A generic empty message that you can re-use to avoid defining duplicated empty messages in your APIs. A typical example is to use it as the request or the response type of an API method. For instance: service Foo { rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty); }
}</pre>
</div>

<div class="method">
    <code class="details" id="executeBatchDml">executeBatchDml(session, body=None, x__xgafv=None)</code>
  <pre>Executes a batch of SQL DML statements. This method allows many statements to be run with lower latency than submitting them sequentially with ExecuteSql. Statements are executed in sequential order. A request can succeed even if a statement fails. The ExecuteBatchDmlResponse.status field in the response provides information about the statement that failed. Clients must inspect this field to determine whether an error occurred. Execution stops after the first failed statement; the remaining statements are not executed.

Args:
  session: string, Required. The session in which the DML statements should be performed. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for ExecuteBatchDml.
  &quot;lastStatements&quot;: True or False, # Optional. If set to `true`, this request marks the end of the transaction. After these statements execute, you must commit or abort the transaction. Attempts to execute any other requests against this transaction (including reads and queries) are rejected. Setting this option might cause some error reporting to be deferred until commit time (for example, validation of unique constraints). Given this, successful execution of statements shouldn&#x27;t be assumed until a subsequent `Commit` call completes successfully.
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;seqno&quot;: &quot;A String&quot;, # Required. A per-transaction sequence number used to identify this request. This field makes each request idempotent such that if the request is received multiple times, at most one succeeds. The sequence number must be monotonically increasing within the transaction. If a request arrives for the first time with an out-of-order sequence number, the transaction might be aborted. Replays of previously handled requests yield the same response as the first execution.
  &quot;statements&quot;: [ # Required. The list of statements to execute in this batch. Statements are executed serially, such that the effects of statement `i` are visible to statement `i+1`. Each statement must be a DML statement. Execution stops at the first failed statement; the remaining statements are not executed. Callers must provide at least one statement.
    { # A single DML statement.
      &quot;paramTypes&quot;: { # It isn&#x27;t always possible for Cloud Spanner to infer the right SQL type from a JSON value. For example, values of type `BYTES` and values of type `STRING` both appear in params as JSON strings. In these cases, `param_types` can be used to specify the exact SQL type for some or all of the SQL statement parameters. See the definition of Type for more information about SQL types.
        &quot;a_key&quot;: { # `Type` indicates the type of a Cloud Spanner value, as might be stored in a table cell or returned from an SQL query.
          &quot;arrayElementType&quot;: # Object with schema name: Type # If code == ARRAY, then `array_element_type` is the type of the array elements.
          &quot;code&quot;: &quot;A String&quot;, # Required. The TypeCode for this type.
          &quot;protoTypeFqn&quot;: &quot;A String&quot;, # If code == PROTO or code == ENUM, then `proto_type_fqn` is the fully qualified name of the proto type representing the proto/enum definition.
          &quot;structType&quot;: { # `StructType` defines the fields of a STRUCT type. # If code == STRUCT, then `struct_type` provides type information for the struct&#x27;s fields.
            &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
              { # Message representing a single field of a struct.
                &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
                &quot;type&quot;: # Object with schema name: Type # The type of the field.
              },
            ],
          },
          &quot;typeAnnotation&quot;: &quot;A String&quot;, # The TypeAnnotationCode that disambiguates SQL type that Spanner will use to represent values of this type during query processing. This is necessary for some type codes because a single TypeCode can be mapped to different SQL types depending on the SQL dialect. type_annotation typically is not needed to process the content of a value (it doesn&#x27;t affect serialization) and clients can ignore it on the read path.
        },
      },
      &quot;params&quot;: { # Parameter names and values that bind to placeholders in the DML string. A parameter placeholder consists of the `@` character followed by the parameter name (for example, `@firstName`). Parameter names can contain letters, numbers, and underscores. Parameters can appear anywhere that a literal value is expected. The same parameter name can be used more than once, for example: `&quot;WHERE id &gt; @msg_id AND id &lt; @msg_id + 100&quot;` It&#x27;s an error to execute a SQL statement with unbound parameters.
        &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
      },
      &quot;sql&quot;: &quot;A String&quot;, # Required. The DML string.
    },
  ],
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # Required. The transaction to use. Must be a read-write transaction. To protect against replays, single-use transactions are not supported. The caller must either supply an existing transaction ID or begin a new transaction.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for ExecuteBatchDml. Contains a list of ResultSet messages, one for each DML statement that has successfully executed, in the same order as the statements in the request. If a statement fails, the status in the response body identifies the cause of the failure. To check for DML statements that failed, use the following approach: 1. Check the status in the response message. The google.rpc.Code enum value `OK` indicates that all statements were executed successfully. 2. If the status was not `OK`, check the number of result sets in the response. If the response contains `N` ResultSet messages, then statement `N+1` in the request failed. Example 1: * Request: 5 DML statements, all executed successfully. * Response: 5 ResultSet messages, with the status `OK`. Example 2: * Request: 5 DML statements. The third statement has a syntax error. * Response: 2 ResultSet messages, and a syntax error (`INVALID_ARGUMENT`) status. The number of ResultSet messages indicates that the third statement failed, and the fourth and fifth statements were not executed.
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction is on a multiplexed session. Pass the precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;resultSets&quot;: [ # One ResultSet for each statement in the request that ran successfully, in the same order as the statements in the request. Each ResultSet does not contain any rows. The ResultSetStats in each ResultSet contain the number of rows modified by the statement. Only the first ResultSet in the response contains valid ResultSetMetadata.
    { # Results from Read or ExecuteSql.
      &quot;metadata&quot;: { # Metadata about a ResultSet or PartialResultSet. # Metadata about the result set, such as row type information.
        &quot;rowType&quot;: { # `StructType` defines the fields of a STRUCT type. # Indicates the field names and types for the rows in the result set. For example, a SQL query like `&quot;SELECT UserId, UserName FROM Users&quot;` could return a `row_type` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
          &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
            { # Message representing a single field of a struct.
              &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
              &quot;type&quot;: # Object with schema name: Type # The type of the field.
            },
          ],
        },
        &quot;transaction&quot;: { # A transaction. # If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.
          &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
          &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
            &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
            &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
          },
          &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        },
        &quot;undeclaredParameters&quot;: { # `StructType` defines the fields of a STRUCT type. # A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like `&quot;SELECT * FROM Users where UserId = @userId and UserName = @userName &quot;` could return a `undeclared_parameters` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
          &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
            { # Message representing a single field of a struct.
              &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
              &quot;type&quot;: # Object with schema name: Type # The type of the field.
            },
          ],
        },
      },
      &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction is on a multiplexed session. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
        &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
        &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
      },
      &quot;rows&quot;: [ # Each element in `rows` is a row whose format is defined by metadata.row_type. The ith element in each row matches the ith field in metadata.row_type. Elements are encoded based on type as described here.
        [
          &quot;&quot;,
        ],
      ],
      &quot;stats&quot;: { # Additional statistics about a ResultSet or PartialResultSet. # Query plan and execution statistics for the SQL statement that produced this result set. These can be requested by setting ExecuteSqlRequest.query_mode. DML statements always produce stats containing the number of rows modified, unless executed using the ExecuteSqlRequest.QueryMode.PLAN ExecuteSqlRequest.query_mode. Other fields might or might not be populated, based on the ExecuteSqlRequest.query_mode.
        &quot;queryPlan&quot;: { # Contains an ordered list of nodes appearing in the query plan. # QueryPlan for the query associated with this result.
          &quot;planNodes&quot;: [ # The nodes in the query plan. Plan nodes are returned in pre-order starting with the plan root. Each PlanNode&#x27;s `id` corresponds to its index in `plan_nodes`.
            { # Node information for nodes appearing in a QueryPlan.plan_nodes.
              &quot;childLinks&quot;: [ # List of child node `index`es and their relationship to this parent.
                { # Metadata associated with a parent-child relationship appearing in a PlanNode.
                  &quot;childIndex&quot;: 42, # The node to which the link points.
                  &quot;type&quot;: &quot;A String&quot;, # The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.
                  &quot;variable&quot;: &quot;A String&quot;, # Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a `TableScan` operator that reads rows from a table will have child links to the `SCALAR` nodes representing the output variables created for each column that is read by the operator. The corresponding `variable` fields will be set to the variable names assigned to the columns.
                },
              ],
              &quot;displayName&quot;: &quot;A String&quot;, # The display name for the node.
              &quot;executionStats&quot;: { # The execution statistics associated with the node, contained in a group of key-value pairs. Only present if the plan was returned as a result of a profile query. For example, number of executions, number of rows/time per execution etc.
                &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
              },
              &quot;index&quot;: 42, # The `PlanNode`&#x27;s index in node list.
              &quot;kind&quot;: &quot;A String&quot;, # Used to determine the type of node. May be needed for visualizing different kinds of nodes differently. For example, If the node is a SCALAR node, it will have a condensed representation which can be used to directly embed a description of the node in its parent.
              &quot;metadata&quot;: { # Attributes relevant to the node contained in a group of key-value pairs. For example, a Parameter Reference node could have the following information in its metadata: { &quot;parameter_reference&quot;: &quot;param1&quot;, &quot;parameter_type&quot;: &quot;array&quot; }
                &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
              },
              &quot;shortRepresentation&quot;: { # Condensed representation of a node and its subtree. Only present for `SCALAR` PlanNode(s). # Condensed representation for SCALAR nodes.
                &quot;description&quot;: &quot;A String&quot;, # A string representation of the expression subtree rooted at this node.
                &quot;subqueries&quot;: { # A mapping of (subquery variable name) -&gt; (subquery node id) for cases where the `description` string of this node references a `SCALAR` subquery contained in the expression subtree rooted at this node. The referenced `SCALAR` subquery may not necessarily be a direct child of this node.
                  &quot;a_key&quot;: 42,
                },
              },
            },
          ],
          &quot;queryAdvice&quot;: { # Output of query advisor analysis. # Optional. The advise/recommendations for a query. Currently this field will be serving index recommendations for a query.
            &quot;indexAdvice&quot;: [ # Optional. Index Recommendation for a query. This is an optional field and the recommendation will only be available when the recommendation guarantees significant improvement in query performance.
              { # Recommendation to add new indexes to run queries more efficiently.
                &quot;ddl&quot;: [ # Optional. DDL statements to add new indexes that will improve the query.
                  &quot;A String&quot;,
                ],
                &quot;improvementFactor&quot;: 3.14, # Optional. Estimated latency improvement factor. For example if the query currently takes 500 ms to run and the estimated latency with new indexes is 100 ms this field will be 5.
              },
            ],
          },
        },
        &quot;queryStats&quot;: { # Aggregated statistics from the execution of the query. Only present when the query is profiled. For example, a query could return the statistics as follows: { &quot;rows_returned&quot;: &quot;3&quot;, &quot;elapsed_time&quot;: &quot;1.22 secs&quot;, &quot;cpu_time&quot;: &quot;1.19 secs&quot; }
          &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
        },
        &quot;rowCountExact&quot;: &quot;A String&quot;, # Standard DML returns an exact count of rows that were modified.
        &quot;rowCountLowerBound&quot;: &quot;A String&quot;, # Partitioned DML doesn&#x27;t offer exactly-once semantics, so it returns a lower bound of the rows modified.
      },
    },
  ],
  &quot;status&quot;: { # The `Status` type defines a logical error model that is suitable for different programming environments, including REST APIs and RPC APIs. It is used by [gRPC](https://github.com/grpc). Each `Status` message contains three pieces of data: error code, error message, and error details. You can find out more about this error model and how to work with it in the [API Design Guide](https://cloud.google.com/apis/design/errors). # If all DML statements are executed successfully, the status is `OK`. Otherwise, the error status of the first failed statement.
    &quot;code&quot;: 42, # The status code, which should be an enum value of google.rpc.Code.
    &quot;details&quot;: [ # A list of messages that carry the error details. There is a common set of message types for APIs to use.
      {
        &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
      },
    ],
    &quot;message&quot;: &quot;A String&quot;, # A developer-facing error message, which should be in English. Any user-facing error message should be localized and sent in the google.rpc.Status.details field, or localized by the client.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="executeSql">executeSql(session, body=None, x__xgafv=None)</code>
  <pre>Executes an SQL statement, returning all results in a single reply. This method can&#x27;t be used to return a result set larger than 10 MiB; if the query yields more data than that, the query fails with a `FAILED_PRECONDITION` error. Operations inside read-write transactions might return `ABORTED`. If this occurs, the application should restart the transaction from the beginning. See Transaction for more details. Larger result sets can be fetched in streaming fashion by calling ExecuteStreamingSql instead. The query string can be SQL or [Graph Query Language (GQL)](https://cloud.google.com/spanner/docs/reference/standard-sql/graph-intro).

Args:
  session: string, Required. The session in which the SQL query should be performed. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for ExecuteSql and ExecuteStreamingSql.
  &quot;dataBoostEnabled&quot;: True or False, # If this is for a partitioned query and this field is set to `true`, the request is executed with Spanner Data Boost independent compute resources. If the field is set to `true` but the request doesn&#x27;t set `partition_token`, the API returns an `INVALID_ARGUMENT` error.
  &quot;directedReadOptions&quot;: { # The `DirectedReadOptions` can be used to indicate which replicas or regions should be used for non-transactional reads or queries. `DirectedReadOptions` can only be specified for a read-only transaction, otherwise the API returns an `INVALID_ARGUMENT` error. # Directed read options for this request.
    &quot;excludeReplicas&quot;: { # An ExcludeReplicas contains a repeated set of ReplicaSelection that should be excluded from serving requests. # `Exclude_replicas` indicates that specified replicas should be excluded from serving requests. Spanner doesn&#x27;t route requests to the replicas in this list.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
    &quot;includeReplicas&quot;: { # An `IncludeReplicas` contains a repeated set of `ReplicaSelection` which indicates the order in which replicas should be considered. # `Include_replicas` indicates the order of replicas (as they appear in this list) to process the request. If `auto_failover_disabled` is set to `true` and all replicas are exhausted without finding a healthy replica, Spanner waits for a replica in the list to become available, requests might fail due to `DEADLINE_EXCEEDED` errors.
      &quot;autoFailoverDisabled&quot;: True or False, # If `true`, Spanner doesn&#x27;t route requests to a replica outside the &lt;`include_replicas` list when all of the specified replicas are unavailable or unhealthy. Default value is `false`.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
  },
  &quot;lastStatement&quot;: True or False, # Optional. If set to `true`, this statement marks the end of the transaction. After this statement executes, you must commit or abort the transaction. Attempts to execute any other requests against this transaction (including reads and queries) are rejected. For DML statements, setting this option might cause some error reporting to be deferred until commit time (for example, validation of unique constraints). Given this, successful execution of a DML statement shouldn&#x27;t be assumed until a subsequent `Commit` call completes successfully.
  &quot;paramTypes&quot;: { # It isn&#x27;t always possible for Cloud Spanner to infer the right SQL type from a JSON value. For example, values of type `BYTES` and values of type `STRING` both appear in params as JSON strings. In these cases, you can use `param_types` to specify the exact SQL type for some or all of the SQL statement parameters. See the definition of Type for more information about SQL types.
    &quot;a_key&quot;: { # `Type` indicates the type of a Cloud Spanner value, as might be stored in a table cell or returned from an SQL query.
      &quot;arrayElementType&quot;: # Object with schema name: Type # If code == ARRAY, then `array_element_type` is the type of the array elements.
      &quot;code&quot;: &quot;A String&quot;, # Required. The TypeCode for this type.
      &quot;protoTypeFqn&quot;: &quot;A String&quot;, # If code == PROTO or code == ENUM, then `proto_type_fqn` is the fully qualified name of the proto type representing the proto/enum definition.
      &quot;structType&quot;: { # `StructType` defines the fields of a STRUCT type. # If code == STRUCT, then `struct_type` provides type information for the struct&#x27;s fields.
        &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
          { # Message representing a single field of a struct.
            &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
            &quot;type&quot;: # Object with schema name: Type # The type of the field.
          },
        ],
      },
      &quot;typeAnnotation&quot;: &quot;A String&quot;, # The TypeAnnotationCode that disambiguates SQL type that Spanner will use to represent values of this type during query processing. This is necessary for some type codes because a single TypeCode can be mapped to different SQL types depending on the SQL dialect. type_annotation typically is not needed to process the content of a value (it doesn&#x27;t affect serialization) and clients can ignore it on the read path.
    },
  },
  &quot;params&quot;: { # Parameter names and values that bind to placeholders in the SQL string. A parameter placeholder consists of the `@` character followed by the parameter name (for example, `@firstName`). Parameter names must conform to the naming requirements of identifiers as specified at https://cloud.google.com/spanner/docs/lexical#identifiers. Parameters can appear anywhere that a literal value is expected. The same parameter name can be used more than once, for example: `&quot;WHERE id &gt; @msg_id AND id &lt; @msg_id + 100&quot;` It&#x27;s an error to execute a SQL statement with unbound parameters.
    &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
  },
  &quot;partitionToken&quot;: &quot;A String&quot;, # If present, results are restricted to the specified partition previously created using `PartitionQuery`. There must be an exact match for the values of fields common to this message and the `PartitionQueryRequest` message used to create this `partition_token`.
  &quot;queryMode&quot;: &quot;A String&quot;, # Used to control the amount of debugging information returned in ResultSetStats. If partition_token is set, query_mode can only be set to QueryMode.NORMAL.
  &quot;queryOptions&quot;: { # Query optimizer configuration. # Query optimizer configuration to use for the given query.
    &quot;optimizerStatisticsPackage&quot;: &quot;A String&quot;, # An option to control the selection of optimizer statistics package. This parameter allows individual queries to use a different query optimizer statistics package. Specifying `latest` as a value instructs Cloud Spanner to use the latest generated statistics package. If not specified, Cloud Spanner uses the statistics package set at the database level options, or the latest package if the database option isn&#x27;t set. The statistics package requested by the query has to be exempt from garbage collection. This can be achieved with the following DDL statement: ```sql ALTER STATISTICS SET OPTIONS (allow_gc=false) ``` The list of available statistics packages can be queried from `INFORMATION_SCHEMA.SPANNER_STATISTICS`. Executing a SQL statement with an invalid optimizer statistics package or with a statistics package that allows garbage collection fails with an `INVALID_ARGUMENT` error.
    &quot;optimizerVersion&quot;: &quot;A String&quot;, # An option to control the selection of optimizer version. This parameter allows individual queries to pick different query optimizer versions. Specifying `latest` as a value instructs Cloud Spanner to use the latest supported query optimizer version. If not specified, Cloud Spanner uses the optimizer version set at the database level options. Any other positive integer (from the list of supported optimizer versions) overrides the default optimizer version for query execution. The list of supported optimizer versions can be queried from `SPANNER_SYS.SUPPORTED_OPTIMIZER_VERSIONS`. Executing a SQL statement with an invalid optimizer version fails with an `INVALID_ARGUMENT` error. See https://cloud.google.com/spanner/docs/query-optimizer/manage-query-optimizer for more information on managing the query optimizer. The `optimizer_version` statement hint has precedence over this setting.
  },
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # If this request is resuming a previously interrupted SQL statement execution, `resume_token` should be copied from the last PartialResultSet yielded before the interruption. Doing this enables the new SQL statement execution to resume where the last one left off. The rest of the request parameters must exactly match the request that yielded this token.
  &quot;seqno&quot;: &quot;A String&quot;, # A per-transaction sequence number used to identify this request. This field makes each request idempotent such that if the request is received multiple times, at most one succeeds. The sequence number must be monotonically increasing within the transaction. If a request arrives for the first time with an out-of-order sequence number, the transaction can be aborted. Replays of previously handled requests yield the same response as the first execution. Required for DML statements. Ignored for queries.
  &quot;sql&quot;: &quot;A String&quot;, # Required. The SQL string.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # The transaction to use. For queries, if none is provided, the default is a temporary read-only transaction with strong concurrency. Standard DML statements require a read-write transaction. To protect against replays, single-use transactions are not supported. The caller must either supply an existing transaction ID or begin a new transaction. Partitioned DML requires an existing Partitioned DML transaction ID.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # Results from Read or ExecuteSql.
  &quot;metadata&quot;: { # Metadata about a ResultSet or PartialResultSet. # Metadata about the result set, such as row type information.
    &quot;rowType&quot;: { # `StructType` defines the fields of a STRUCT type. # Indicates the field names and types for the rows in the result set. For example, a SQL query like `&quot;SELECT UserId, UserName FROM Users&quot;` could return a `row_type` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
    &quot;transaction&quot;: { # A transaction. # If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.
      &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
      &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
        &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
        &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
      },
      &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
    },
    &quot;undeclaredParameters&quot;: { # `StructType` defines the fields of a STRUCT type. # A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like `&quot;SELECT * FROM Users where UserId = @userId and UserName = @userName &quot;` could return a `undeclared_parameters` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
  },
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction is on a multiplexed session. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;rows&quot;: [ # Each element in `rows` is a row whose format is defined by metadata.row_type. The ith element in each row matches the ith field in metadata.row_type. Elements are encoded based on type as described here.
    [
      &quot;&quot;,
    ],
  ],
  &quot;stats&quot;: { # Additional statistics about a ResultSet or PartialResultSet. # Query plan and execution statistics for the SQL statement that produced this result set. These can be requested by setting ExecuteSqlRequest.query_mode. DML statements always produce stats containing the number of rows modified, unless executed using the ExecuteSqlRequest.QueryMode.PLAN ExecuteSqlRequest.query_mode. Other fields might or might not be populated, based on the ExecuteSqlRequest.query_mode.
    &quot;queryPlan&quot;: { # Contains an ordered list of nodes appearing in the query plan. # QueryPlan for the query associated with this result.
      &quot;planNodes&quot;: [ # The nodes in the query plan. Plan nodes are returned in pre-order starting with the plan root. Each PlanNode&#x27;s `id` corresponds to its index in `plan_nodes`.
        { # Node information for nodes appearing in a QueryPlan.plan_nodes.
          &quot;childLinks&quot;: [ # List of child node `index`es and their relationship to this parent.
            { # Metadata associated with a parent-child relationship appearing in a PlanNode.
              &quot;childIndex&quot;: 42, # The node to which the link points.
              &quot;type&quot;: &quot;A String&quot;, # The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.
              &quot;variable&quot;: &quot;A String&quot;, # Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a `TableScan` operator that reads rows from a table will have child links to the `SCALAR` nodes representing the output variables created for each column that is read by the operator. The corresponding `variable` fields will be set to the variable names assigned to the columns.
            },
          ],
          &quot;displayName&quot;: &quot;A String&quot;, # The display name for the node.
          &quot;executionStats&quot;: { # The execution statistics associated with the node, contained in a group of key-value pairs. Only present if the plan was returned as a result of a profile query. For example, number of executions, number of rows/time per execution etc.
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;index&quot;: 42, # The `PlanNode`&#x27;s index in node list.
          &quot;kind&quot;: &quot;A String&quot;, # Used to determine the type of node. May be needed for visualizing different kinds of nodes differently. For example, If the node is a SCALAR node, it will have a condensed representation which can be used to directly embed a description of the node in its parent.
          &quot;metadata&quot;: { # Attributes relevant to the node contained in a group of key-value pairs. For example, a Parameter Reference node could have the following information in its metadata: { &quot;parameter_reference&quot;: &quot;param1&quot;, &quot;parameter_type&quot;: &quot;array&quot; }
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;shortRepresentation&quot;: { # Condensed representation of a node and its subtree. Only present for `SCALAR` PlanNode(s). # Condensed representation for SCALAR nodes.
            &quot;description&quot;: &quot;A String&quot;, # A string representation of the expression subtree rooted at this node.
            &quot;subqueries&quot;: { # A mapping of (subquery variable name) -&gt; (subquery node id) for cases where the `description` string of this node references a `SCALAR` subquery contained in the expression subtree rooted at this node. The referenced `SCALAR` subquery may not necessarily be a direct child of this node.
              &quot;a_key&quot;: 42,
            },
          },
        },
      ],
      &quot;queryAdvice&quot;: { # Output of query advisor analysis. # Optional. The advise/recommendations for a query. Currently this field will be serving index recommendations for a query.
        &quot;indexAdvice&quot;: [ # Optional. Index Recommendation for a query. This is an optional field and the recommendation will only be available when the recommendation guarantees significant improvement in query performance.
          { # Recommendation to add new indexes to run queries more efficiently.
            &quot;ddl&quot;: [ # Optional. DDL statements to add new indexes that will improve the query.
              &quot;A String&quot;,
            ],
            &quot;improvementFactor&quot;: 3.14, # Optional. Estimated latency improvement factor. For example if the query currently takes 500 ms to run and the estimated latency with new indexes is 100 ms this field will be 5.
          },
        ],
      },
    },
    &quot;queryStats&quot;: { # Aggregated statistics from the execution of the query. Only present when the query is profiled. For example, a query could return the statistics as follows: { &quot;rows_returned&quot;: &quot;3&quot;, &quot;elapsed_time&quot;: &quot;1.22 secs&quot;, &quot;cpu_time&quot;: &quot;1.19 secs&quot; }
      &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
    },
    &quot;rowCountExact&quot;: &quot;A String&quot;, # Standard DML returns an exact count of rows that were modified.
    &quot;rowCountLowerBound&quot;: &quot;A String&quot;, # Partitioned DML doesn&#x27;t offer exactly-once semantics, so it returns a lower bound of the rows modified.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="executeStreamingSql">executeStreamingSql(session, body=None, x__xgafv=None)</code>
  <pre>Like ExecuteSql, except returns the result set as a stream. Unlike ExecuteSql, there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB. The query string can be SQL or [Graph Query Language (GQL)](https://cloud.google.com/spanner/docs/reference/standard-sql/graph-intro).

Args:
  session: string, Required. The session in which the SQL query should be performed. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for ExecuteSql and ExecuteStreamingSql.
  &quot;dataBoostEnabled&quot;: True or False, # If this is for a partitioned query and this field is set to `true`, the request is executed with Spanner Data Boost independent compute resources. If the field is set to `true` but the request doesn&#x27;t set `partition_token`, the API returns an `INVALID_ARGUMENT` error.
  &quot;directedReadOptions&quot;: { # The `DirectedReadOptions` can be used to indicate which replicas or regions should be used for non-transactional reads or queries. `DirectedReadOptions` can only be specified for a read-only transaction, otherwise the API returns an `INVALID_ARGUMENT` error. # Directed read options for this request.
    &quot;excludeReplicas&quot;: { # An ExcludeReplicas contains a repeated set of ReplicaSelection that should be excluded from serving requests. # `Exclude_replicas` indicates that specified replicas should be excluded from serving requests. Spanner doesn&#x27;t route requests to the replicas in this list.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
    &quot;includeReplicas&quot;: { # An `IncludeReplicas` contains a repeated set of `ReplicaSelection` which indicates the order in which replicas should be considered. # `Include_replicas` indicates the order of replicas (as they appear in this list) to process the request. If `auto_failover_disabled` is set to `true` and all replicas are exhausted without finding a healthy replica, Spanner waits for a replica in the list to become available, requests might fail due to `DEADLINE_EXCEEDED` errors.
      &quot;autoFailoverDisabled&quot;: True or False, # If `true`, Spanner doesn&#x27;t route requests to a replica outside the &lt;`include_replicas` list when all of the specified replicas are unavailable or unhealthy. Default value is `false`.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
  },
  &quot;lastStatement&quot;: True or False, # Optional. If set to `true`, this statement marks the end of the transaction. After this statement executes, you must commit or abort the transaction. Attempts to execute any other requests against this transaction (including reads and queries) are rejected. For DML statements, setting this option might cause some error reporting to be deferred until commit time (for example, validation of unique constraints). Given this, successful execution of a DML statement shouldn&#x27;t be assumed until a subsequent `Commit` call completes successfully.
  &quot;paramTypes&quot;: { # It isn&#x27;t always possible for Cloud Spanner to infer the right SQL type from a JSON value. For example, values of type `BYTES` and values of type `STRING` both appear in params as JSON strings. In these cases, you can use `param_types` to specify the exact SQL type for some or all of the SQL statement parameters. See the definition of Type for more information about SQL types.
    &quot;a_key&quot;: { # `Type` indicates the type of a Cloud Spanner value, as might be stored in a table cell or returned from an SQL query.
      &quot;arrayElementType&quot;: # Object with schema name: Type # If code == ARRAY, then `array_element_type` is the type of the array elements.
      &quot;code&quot;: &quot;A String&quot;, # Required. The TypeCode for this type.
      &quot;protoTypeFqn&quot;: &quot;A String&quot;, # If code == PROTO or code == ENUM, then `proto_type_fqn` is the fully qualified name of the proto type representing the proto/enum definition.
      &quot;structType&quot;: { # `StructType` defines the fields of a STRUCT type. # If code == STRUCT, then `struct_type` provides type information for the struct&#x27;s fields.
        &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
          { # Message representing a single field of a struct.
            &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
            &quot;type&quot;: # Object with schema name: Type # The type of the field.
          },
        ],
      },
      &quot;typeAnnotation&quot;: &quot;A String&quot;, # The TypeAnnotationCode that disambiguates SQL type that Spanner will use to represent values of this type during query processing. This is necessary for some type codes because a single TypeCode can be mapped to different SQL types depending on the SQL dialect. type_annotation typically is not needed to process the content of a value (it doesn&#x27;t affect serialization) and clients can ignore it on the read path.
    },
  },
  &quot;params&quot;: { # Parameter names and values that bind to placeholders in the SQL string. A parameter placeholder consists of the `@` character followed by the parameter name (for example, `@firstName`). Parameter names must conform to the naming requirements of identifiers as specified at https://cloud.google.com/spanner/docs/lexical#identifiers. Parameters can appear anywhere that a literal value is expected. The same parameter name can be used more than once, for example: `&quot;WHERE id &gt; @msg_id AND id &lt; @msg_id + 100&quot;` It&#x27;s an error to execute a SQL statement with unbound parameters.
    &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
  },
  &quot;partitionToken&quot;: &quot;A String&quot;, # If present, results are restricted to the specified partition previously created using `PartitionQuery`. There must be an exact match for the values of fields common to this message and the `PartitionQueryRequest` message used to create this `partition_token`.
  &quot;queryMode&quot;: &quot;A String&quot;, # Used to control the amount of debugging information returned in ResultSetStats. If partition_token is set, query_mode can only be set to QueryMode.NORMAL.
  &quot;queryOptions&quot;: { # Query optimizer configuration. # Query optimizer configuration to use for the given query.
    &quot;optimizerStatisticsPackage&quot;: &quot;A String&quot;, # An option to control the selection of optimizer statistics package. This parameter allows individual queries to use a different query optimizer statistics package. Specifying `latest` as a value instructs Cloud Spanner to use the latest generated statistics package. If not specified, Cloud Spanner uses the statistics package set at the database level options, or the latest package if the database option isn&#x27;t set. The statistics package requested by the query has to be exempt from garbage collection. This can be achieved with the following DDL statement: ```sql ALTER STATISTICS SET OPTIONS (allow_gc=false) ``` The list of available statistics packages can be queried from `INFORMATION_SCHEMA.SPANNER_STATISTICS`. Executing a SQL statement with an invalid optimizer statistics package or with a statistics package that allows garbage collection fails with an `INVALID_ARGUMENT` error.
    &quot;optimizerVersion&quot;: &quot;A String&quot;, # An option to control the selection of optimizer version. This parameter allows individual queries to pick different query optimizer versions. Specifying `latest` as a value instructs Cloud Spanner to use the latest supported query optimizer version. If not specified, Cloud Spanner uses the optimizer version set at the database level options. Any other positive integer (from the list of supported optimizer versions) overrides the default optimizer version for query execution. The list of supported optimizer versions can be queried from `SPANNER_SYS.SUPPORTED_OPTIMIZER_VERSIONS`. Executing a SQL statement with an invalid optimizer version fails with an `INVALID_ARGUMENT` error. See https://cloud.google.com/spanner/docs/query-optimizer/manage-query-optimizer for more information on managing the query optimizer. The `optimizer_version` statement hint has precedence over this setting.
  },
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # If this request is resuming a previously interrupted SQL statement execution, `resume_token` should be copied from the last PartialResultSet yielded before the interruption. Doing this enables the new SQL statement execution to resume where the last one left off. The rest of the request parameters must exactly match the request that yielded this token.
  &quot;seqno&quot;: &quot;A String&quot;, # A per-transaction sequence number used to identify this request. This field makes each request idempotent such that if the request is received multiple times, at most one succeeds. The sequence number must be monotonically increasing within the transaction. If a request arrives for the first time with an out-of-order sequence number, the transaction can be aborted. Replays of previously handled requests yield the same response as the first execution. Required for DML statements. Ignored for queries.
  &quot;sql&quot;: &quot;A String&quot;, # Required. The SQL string.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # The transaction to use. For queries, if none is provided, the default is a temporary read-only transaction with strong concurrency. Standard DML statements require a read-write transaction. To protect against replays, single-use transactions are not supported. The caller must either supply an existing transaction ID or begin a new transaction. Partitioned DML requires an existing Partitioned DML transaction ID.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # Partial results from a streaming read or SQL query. Streaming reads and SQL queries better tolerate large result sets, large rows, and large values, but are a little trickier to consume.
  &quot;chunkedValue&quot;: True or False, # If true, then the final value in values is chunked, and must be combined with more values from subsequent `PartialResultSet`s to obtain a complete field value.
  &quot;last&quot;: True or False, # Optional. Indicates whether this is the last `PartialResultSet` in the stream. The server might optionally set this field. Clients shouldn&#x27;t rely on this field being set in all cases.
  &quot;metadata&quot;: { # Metadata about a ResultSet or PartialResultSet. # Metadata about the result set, such as row type information. Only present in the first response.
    &quot;rowType&quot;: { # `StructType` defines the fields of a STRUCT type. # Indicates the field names and types for the rows in the result set. For example, a SQL query like `&quot;SELECT UserId, UserName FROM Users&quot;` could return a `row_type` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
    &quot;transaction&quot;: { # A transaction. # If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.
      &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
      &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
        &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
        &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
      },
      &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
    },
    &quot;undeclaredParameters&quot;: { # `StructType` defines the fields of a STRUCT type. # A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like `&quot;SELECT * FROM Users where UserId = @userId and UserName = @userName &quot;` could return a `undeclared_parameters` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
  },
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction has multiplexed sessions enabled. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # Streaming calls might be interrupted for a variety of reasons, such as TCP connection loss. If this occurs, the stream of results can be resumed by re-sending the original request and including `resume_token`. Note that executing any other transaction in the same session invalidates the token.
  &quot;stats&quot;: { # Additional statistics about a ResultSet or PartialResultSet. # Query plan and execution statistics for the statement that produced this streaming result set. These can be requested by setting ExecuteSqlRequest.query_mode and are sent only once with the last response in the stream. This field is also present in the last response for DML statements.
    &quot;queryPlan&quot;: { # Contains an ordered list of nodes appearing in the query plan. # QueryPlan for the query associated with this result.
      &quot;planNodes&quot;: [ # The nodes in the query plan. Plan nodes are returned in pre-order starting with the plan root. Each PlanNode&#x27;s `id` corresponds to its index in `plan_nodes`.
        { # Node information for nodes appearing in a QueryPlan.plan_nodes.
          &quot;childLinks&quot;: [ # List of child node `index`es and their relationship to this parent.
            { # Metadata associated with a parent-child relationship appearing in a PlanNode.
              &quot;childIndex&quot;: 42, # The node to which the link points.
              &quot;type&quot;: &quot;A String&quot;, # The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.
              &quot;variable&quot;: &quot;A String&quot;, # Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a `TableScan` operator that reads rows from a table will have child links to the `SCALAR` nodes representing the output variables created for each column that is read by the operator. The corresponding `variable` fields will be set to the variable names assigned to the columns.
            },
          ],
          &quot;displayName&quot;: &quot;A String&quot;, # The display name for the node.
          &quot;executionStats&quot;: { # The execution statistics associated with the node, contained in a group of key-value pairs. Only present if the plan was returned as a result of a profile query. For example, number of executions, number of rows/time per execution etc.
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;index&quot;: 42, # The `PlanNode`&#x27;s index in node list.
          &quot;kind&quot;: &quot;A String&quot;, # Used to determine the type of node. May be needed for visualizing different kinds of nodes differently. For example, If the node is a SCALAR node, it will have a condensed representation which can be used to directly embed a description of the node in its parent.
          &quot;metadata&quot;: { # Attributes relevant to the node contained in a group of key-value pairs. For example, a Parameter Reference node could have the following information in its metadata: { &quot;parameter_reference&quot;: &quot;param1&quot;, &quot;parameter_type&quot;: &quot;array&quot; }
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;shortRepresentation&quot;: { # Condensed representation of a node and its subtree. Only present for `SCALAR` PlanNode(s). # Condensed representation for SCALAR nodes.
            &quot;description&quot;: &quot;A String&quot;, # A string representation of the expression subtree rooted at this node.
            &quot;subqueries&quot;: { # A mapping of (subquery variable name) -&gt; (subquery node id) for cases where the `description` string of this node references a `SCALAR` subquery contained in the expression subtree rooted at this node. The referenced `SCALAR` subquery may not necessarily be a direct child of this node.
              &quot;a_key&quot;: 42,
            },
          },
        },
      ],
      &quot;queryAdvice&quot;: { # Output of query advisor analysis. # Optional. The advise/recommendations for a query. Currently this field will be serving index recommendations for a query.
        &quot;indexAdvice&quot;: [ # Optional. Index Recommendation for a query. This is an optional field and the recommendation will only be available when the recommendation guarantees significant improvement in query performance.
          { # Recommendation to add new indexes to run queries more efficiently.
            &quot;ddl&quot;: [ # Optional. DDL statements to add new indexes that will improve the query.
              &quot;A String&quot;,
            ],
            &quot;improvementFactor&quot;: 3.14, # Optional. Estimated latency improvement factor. For example if the query currently takes 500 ms to run and the estimated latency with new indexes is 100 ms this field will be 5.
          },
        ],
      },
    },
    &quot;queryStats&quot;: { # Aggregated statistics from the execution of the query. Only present when the query is profiled. For example, a query could return the statistics as follows: { &quot;rows_returned&quot;: &quot;3&quot;, &quot;elapsed_time&quot;: &quot;1.22 secs&quot;, &quot;cpu_time&quot;: &quot;1.19 secs&quot; }
      &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
    },
    &quot;rowCountExact&quot;: &quot;A String&quot;, # Standard DML returns an exact count of rows that were modified.
    &quot;rowCountLowerBound&quot;: &quot;A String&quot;, # Partitioned DML doesn&#x27;t offer exactly-once semantics, so it returns a lower bound of the rows modified.
  },
  &quot;values&quot;: [ # A streamed result set consists of a stream of values, which might be split into many `PartialResultSet` messages to accommodate large rows and/or large values. Every N complete values defines a row, where N is equal to the number of entries in metadata.row_type.fields. Most values are encoded based on type as described here. It&#x27;s possible that the last value in values is &quot;chunked&quot;, meaning that the rest of the value is sent in subsequent `PartialResultSet`(s). This is denoted by the chunked_value field. Two or more chunked values can be merged to form a complete value as follows: * `bool/number/null`: can&#x27;t be chunked * `string`: concatenate the strings * `list`: concatenate the lists. If the last element in a list is a `string`, `list`, or `object`, merge it with the first element in the next list by applying these rules recursively. * `object`: concatenate the (field name, field value) pairs. If a field name is duplicated, then apply these rules recursively to merge the field values. Some examples of merging: Strings are concatenated. &quot;foo&quot;, &quot;bar&quot; =&gt; &quot;foobar&quot; Lists of non-strings are concatenated. [2, 3], [4] =&gt; [2, 3, 4] Lists are concatenated, but the last and first elements are merged because they are strings. [&quot;a&quot;, &quot;b&quot;], [&quot;c&quot;, &quot;d&quot;] =&gt; [&quot;a&quot;, &quot;bc&quot;, &quot;d&quot;] Lists are concatenated, but the last and first elements are merged because they are lists. Recursively, the last and first elements of the inner lists are merged because they are strings. [&quot;a&quot;, [&quot;b&quot;, &quot;c&quot;]], [[&quot;d&quot;], &quot;e&quot;] =&gt; [&quot;a&quot;, [&quot;b&quot;, &quot;cd&quot;], &quot;e&quot;] Non-overlapping object fields are combined. {&quot;a&quot;: &quot;1&quot;}, {&quot;b&quot;: &quot;2&quot;} =&gt; {&quot;a&quot;: &quot;1&quot;, &quot;b&quot;: 2&quot;} Overlapping object fields are merged. {&quot;a&quot;: &quot;1&quot;}, {&quot;a&quot;: &quot;2&quot;} =&gt; {&quot;a&quot;: &quot;12&quot;} Examples of merging objects containing lists of strings. {&quot;a&quot;: [&quot;1&quot;]}, {&quot;a&quot;: [&quot;2&quot;]} =&gt; {&quot;a&quot;: [&quot;12&quot;]} For a more complete example, suppose a streaming SQL query is yielding a result set whose rows contain a single string field. The following `PartialResultSet`s might be yielded: { &quot;metadata&quot;: { ... } &quot;values&quot;: [&quot;Hello&quot;, &quot;W&quot;] &quot;chunked_value&quot;: true &quot;resume_token&quot;: &quot;Af65...&quot; } { &quot;values&quot;: [&quot;orl&quot;] &quot;chunked_value&quot;: true } { &quot;values&quot;: [&quot;d&quot;] &quot;resume_token&quot;: &quot;Zx1B...&quot; } This sequence of `PartialResultSet`s encodes two rows, one containing the field value `&quot;Hello&quot;`, and a second containing the field value `&quot;World&quot; = &quot;W&quot; + &quot;orl&quot; + &quot;d&quot;`. Not all `PartialResultSet`s contain a `resume_token`. Execution can only be resumed from a previously yielded `resume_token`. For the above sequence of `PartialResultSet`s, resuming the query with `&quot;resume_token&quot;: &quot;Af65...&quot;` yields results from the `PartialResultSet` with value &quot;orl&quot;.
    &quot;&quot;,
  ],
}</pre>
</div>

<div class="method">
    <code class="details" id="get">get(name, x__xgafv=None)</code>
  <pre>Gets a session. Returns `NOT_FOUND` if the session doesn&#x27;t exist. This is mainly useful for determining whether a session is still alive.

Args:
  name: string, Required. The name of the session to retrieve. (required)
  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A session in the Cloud Spanner API.
  &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
  &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
  &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
  &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
    &quot;a_key&quot;: &quot;A String&quot;,
  },
  &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
  &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
}</pre>
</div>

<div class="method">
    <code class="details" id="list">list(database, filter=None, pageSize=None, pageToken=None, x__xgafv=None)</code>
  <pre>Lists all sessions in a given database.

Args:
  database: string, Required. The database in which to list sessions. (required)
  filter: string, An expression for filtering the results of the request. Filter rules are case insensitive. The fields eligible for filtering are: * `labels.key` where key is the name of a label Some examples of using filters are: * `labels.env:*` --&gt; The session has the label &quot;env&quot;. * `labels.env:dev` --&gt; The session has the label &quot;env&quot; and the value of the label contains the string &quot;dev&quot;.
  pageSize: integer, Number of sessions to be returned in the response. If 0 or less, defaults to the server&#x27;s maximum allowed page size.
  pageToken: string, If non-empty, `page_token` should contain a next_page_token from a previous ListSessionsResponse.
  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for ListSessions.
  &quot;nextPageToken&quot;: &quot;A String&quot;, # `next_page_token` can be sent in a subsequent ListSessions call to fetch more of the matching sessions.
  &quot;sessions&quot;: [ # The list of requested sessions.
    { # A session in the Cloud Spanner API.
      &quot;approximateLastUseTime&quot;: &quot;A String&quot;, # Output only. The approximate timestamp when the session is last used. It&#x27;s typically earlier than the actual last use time.
      &quot;createTime&quot;: &quot;A String&quot;, # Output only. The timestamp when the session is created.
      &quot;creatorRole&quot;: &quot;A String&quot;, # The database role which created this session.
      &quot;labels&quot;: { # The labels for the session. * Label keys must be between 1 and 63 characters long and must conform to the following regular expression: `[a-z]([-a-z0-9]*[a-z0-9])?`. * Label values must be between 0 and 63 characters long and must conform to the regular expression `([a-z]([-a-z0-9]*[a-z0-9])?)?`. * No more than 64 labels can be associated with a given session. See https://goo.gl/xmQnxf for more information on and examples of labels.
        &quot;a_key&quot;: &quot;A String&quot;,
      },
      &quot;multiplexed&quot;: True or False, # Optional. If `true`, specifies a multiplexed session. Use a multiplexed session for multiple, concurrent read-only operations. Don&#x27;t use them for read-write transactions, partitioned reads, or partitioned queries. Use `sessions.create` to create multiplexed sessions. Don&#x27;t use BatchCreateSessions to create a multiplexed session. You can&#x27;t delete or list multiplexed sessions.
      &quot;name&quot;: &quot;A String&quot;, # Output only. The name of the session. This is always system-assigned.
    },
  ],
}</pre>
</div>

<div class="method">
    <code class="details" id="list_next">list_next()</code>
  <pre>Retrieves the next page of results.

        Args:
          previous_request: The request for the previous page. (required)
          previous_response: The response from the request for the previous page. (required)

        Returns:
          A request object that you can call &#x27;execute()&#x27; on to request the next
          page. Returns None if there are no more items in the collection.
        </pre>
</div>

<div class="method">
    <code class="details" id="partitionQuery">partitionQuery(session, body=None, x__xgafv=None)</code>
  <pre>Creates a set of partition tokens that can be used to execute a query operation in parallel. Each of the returned partition tokens can be used by ExecuteStreamingSql to specify a subset of the query result to read. The same session and read-only transaction must be used by the `PartitionQueryRequest` used to create the partition tokens and the `ExecuteSqlRequests` that use the partition tokens. Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn&#x27;t possible to resume the query, and the whole operation must be restarted from the beginning.

Args:
  session: string, Required. The session used to create the partitions. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for PartitionQuery
  &quot;paramTypes&quot;: { # It isn&#x27;t always possible for Cloud Spanner to infer the right SQL type from a JSON value. For example, values of type `BYTES` and values of type `STRING` both appear in params as JSON strings. In these cases, `param_types` can be used to specify the exact SQL type for some or all of the SQL query parameters. See the definition of Type for more information about SQL types.
    &quot;a_key&quot;: { # `Type` indicates the type of a Cloud Spanner value, as might be stored in a table cell or returned from an SQL query.
      &quot;arrayElementType&quot;: # Object with schema name: Type # If code == ARRAY, then `array_element_type` is the type of the array elements.
      &quot;code&quot;: &quot;A String&quot;, # Required. The TypeCode for this type.
      &quot;protoTypeFqn&quot;: &quot;A String&quot;, # If code == PROTO or code == ENUM, then `proto_type_fqn` is the fully qualified name of the proto type representing the proto/enum definition.
      &quot;structType&quot;: { # `StructType` defines the fields of a STRUCT type. # If code == STRUCT, then `struct_type` provides type information for the struct&#x27;s fields.
        &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
          { # Message representing a single field of a struct.
            &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
            &quot;type&quot;: # Object with schema name: Type # The type of the field.
          },
        ],
      },
      &quot;typeAnnotation&quot;: &quot;A String&quot;, # The TypeAnnotationCode that disambiguates SQL type that Spanner will use to represent values of this type during query processing. This is necessary for some type codes because a single TypeCode can be mapped to different SQL types depending on the SQL dialect. type_annotation typically is not needed to process the content of a value (it doesn&#x27;t affect serialization) and clients can ignore it on the read path.
    },
  },
  &quot;params&quot;: { # Parameter names and values that bind to placeholders in the SQL string. A parameter placeholder consists of the `@` character followed by the parameter name (for example, `@firstName`). Parameter names can contain letters, numbers, and underscores. Parameters can appear anywhere that a literal value is expected. The same parameter name can be used more than once, for example: `&quot;WHERE id &gt; @msg_id AND id &lt; @msg_id + 100&quot;` It&#x27;s an error to execute a SQL statement with unbound parameters.
    &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
  },
  &quot;partitionOptions&quot;: { # Options for a `PartitionQueryRequest` and `PartitionReadRequest`. # Additional options that affect how many partitions are created.
    &quot;maxPartitions&quot;: &quot;A String&quot;, # **Note:** This hint is currently ignored by `PartitionQuery` and `PartitionRead` requests. The desired maximum number of partitions to return. For example, this might be set to the number of workers available. The default for this option is currently 10,000. The maximum value is currently 200,000. This is only a hint. The actual number of partitions returned can be smaller or larger than this maximum count request.
    &quot;partitionSizeBytes&quot;: &quot;A String&quot;, # **Note:** This hint is currently ignored by `PartitionQuery` and `PartitionRead` requests. The desired data size for each partition generated. The default for this option is currently 1 GiB. This is only a hint. The actual size of each partition can be smaller or larger than this size request.
  },
  &quot;sql&quot;: &quot;A String&quot;, # Required. The query request to generate partitions for. The request fails if the query isn&#x27;t root partitionable. For a query to be root partitionable, it needs to satisfy a few conditions. For example, if the query execution plan contains a distributed union operator, then it must be the first operator in the plan. For more information about other conditions, see [Read data in parallel](https://cloud.google.com/spanner/docs/reads#read_data_in_parallel). The query request must not contain DML commands, such as `INSERT`, `UPDATE`, or `DELETE`. Use `ExecuteStreamingSql` with a `PartitionedDml` transaction for large, partition-friendly DML operations.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # Read-only snapshot transactions are supported, read and write and single-use transactions are not.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for PartitionQuery or PartitionRead
  &quot;partitions&quot;: [ # Partitions created by this request.
    { # Information returned for each partition returned in a PartitionResponse.
      &quot;partitionToken&quot;: &quot;A String&quot;, # This token can be passed to `Read`, `StreamingRead`, `ExecuteSql`, or `ExecuteStreamingSql` requests to restrict the results to those identified by this partition token.
    },
  ],
  &quot;transaction&quot;: { # A transaction. # Transaction created by this request.
    &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
    &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
      &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
      &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
    },
    &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="partitionRead">partitionRead(session, body=None, x__xgafv=None)</code>
  <pre>Creates a set of partition tokens that can be used to execute a read operation in parallel. Each of the returned partition tokens can be used by StreamingRead to specify a subset of the read result to read. The same session and read-only transaction must be used by the `PartitionReadRequest` used to create the partition tokens and the `ReadRequests` that use the partition tokens. There are no ordering guarantees on rows returned among the returned partition tokens, or even within each individual `StreamingRead` call issued with a `partition_token`. Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it isn&#x27;t possible to resume the read, and the whole operation must be restarted from the beginning.

Args:
  session: string, Required. The session used to create the partitions. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for PartitionRead
  &quot;columns&quot;: [ # The columns of table to be returned for each row matching this request.
    &quot;A String&quot;,
  ],
  &quot;index&quot;: &quot;A String&quot;, # If non-empty, the name of an index on table. This index is used instead of the table primary key when interpreting key_set and sorting result rows. See key_set for further information.
  &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. `key_set` identifies the rows to be yielded. `key_set` names the primary keys of the rows in table to be yielded, unless index is present. If index is present, then key_set instead names index keys in index. It isn&#x27;t an error for the `key_set` to name rows that don&#x27;t exist in the database. Read yields nothing for nonexistent rows.
    &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
    &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
      [
        &quot;&quot;,
      ],
    ],
    &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
      { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
        &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
          &quot;&quot;,
        ],
        &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
          &quot;&quot;,
        ],
        &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
          &quot;&quot;,
        ],
        &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
          &quot;&quot;,
        ],
      },
    ],
  },
  &quot;partitionOptions&quot;: { # Options for a `PartitionQueryRequest` and `PartitionReadRequest`. # Additional options that affect how many partitions are created.
    &quot;maxPartitions&quot;: &quot;A String&quot;, # **Note:** This hint is currently ignored by `PartitionQuery` and `PartitionRead` requests. The desired maximum number of partitions to return. For example, this might be set to the number of workers available. The default for this option is currently 10,000. The maximum value is currently 200,000. This is only a hint. The actual number of partitions returned can be smaller or larger than this maximum count request.
    &quot;partitionSizeBytes&quot;: &quot;A String&quot;, # **Note:** This hint is currently ignored by `PartitionQuery` and `PartitionRead` requests. The desired data size for each partition generated. The default for this option is currently 1 GiB. This is only a hint. The actual size of each partition can be smaller or larger than this size request.
  },
  &quot;table&quot;: &quot;A String&quot;, # Required. The name of the table in the database to be read.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # Read only snapshot transactions are supported, read/write and single use transactions are not.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # The response for PartitionQuery or PartitionRead
  &quot;partitions&quot;: [ # Partitions created by this request.
    { # Information returned for each partition returned in a PartitionResponse.
      &quot;partitionToken&quot;: &quot;A String&quot;, # This token can be passed to `Read`, `StreamingRead`, `ExecuteSql`, or `ExecuteStreamingSql` requests to restrict the results to those identified by this partition token.
    },
  ],
  &quot;transaction&quot;: { # A transaction. # Transaction created by this request.
    &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
    &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
      &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
      &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
    },
    &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="read">read(session, body=None, x__xgafv=None)</code>
  <pre>Reads rows from the database using key lookups and scans, as a simple key/value style alternative to ExecuteSql. This method can&#x27;t be used to return a result set larger than 10 MiB; if the read matches more data than that, the read fails with a `FAILED_PRECONDITION` error. Reads inside read-write transactions might return `ABORTED`. If this occurs, the application should restart the transaction from the beginning. See Transaction for more details. Larger result sets can be yielded in streaming fashion by calling StreamingRead instead.

Args:
  session: string, Required. The session in which the read should be performed. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for Read and StreamingRead.
  &quot;columns&quot;: [ # Required. The columns of table to be returned for each row matching this request.
    &quot;A String&quot;,
  ],
  &quot;dataBoostEnabled&quot;: True or False, # If this is for a partitioned read and this field is set to `true`, the request is executed with Spanner Data Boost independent compute resources. If the field is set to `true` but the request doesn&#x27;t set `partition_token`, the API returns an `INVALID_ARGUMENT` error.
  &quot;directedReadOptions&quot;: { # The `DirectedReadOptions` can be used to indicate which replicas or regions should be used for non-transactional reads or queries. `DirectedReadOptions` can only be specified for a read-only transaction, otherwise the API returns an `INVALID_ARGUMENT` error. # Directed read options for this request.
    &quot;excludeReplicas&quot;: { # An ExcludeReplicas contains a repeated set of ReplicaSelection that should be excluded from serving requests. # `Exclude_replicas` indicates that specified replicas should be excluded from serving requests. Spanner doesn&#x27;t route requests to the replicas in this list.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
    &quot;includeReplicas&quot;: { # An `IncludeReplicas` contains a repeated set of `ReplicaSelection` which indicates the order in which replicas should be considered. # `Include_replicas` indicates the order of replicas (as they appear in this list) to process the request. If `auto_failover_disabled` is set to `true` and all replicas are exhausted without finding a healthy replica, Spanner waits for a replica in the list to become available, requests might fail due to `DEADLINE_EXCEEDED` errors.
      &quot;autoFailoverDisabled&quot;: True or False, # If `true`, Spanner doesn&#x27;t route requests to a replica outside the &lt;`include_replicas` list when all of the specified replicas are unavailable or unhealthy. Default value is `false`.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
  },
  &quot;index&quot;: &quot;A String&quot;, # If non-empty, the name of an index on table. This index is used instead of the table primary key when interpreting key_set and sorting result rows. See key_set for further information.
  &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. `key_set` identifies the rows to be yielded. `key_set` names the primary keys of the rows in table to be yielded, unless index is present. If index is present, then key_set instead names index keys in index. If the partition_token field is empty, rows are yielded in table primary key order (if index is empty) or index key order (if index is non-empty). If the partition_token field isn&#x27;t empty, rows are yielded in an unspecified order. It isn&#x27;t an error for the `key_set` to name rows that don&#x27;t exist in the database. Read yields nothing for nonexistent rows.
    &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
    &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
      [
        &quot;&quot;,
      ],
    ],
    &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
      { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
        &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
          &quot;&quot;,
        ],
        &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
          &quot;&quot;,
        ],
        &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
          &quot;&quot;,
        ],
        &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
          &quot;&quot;,
        ],
      },
    ],
  },
  &quot;limit&quot;: &quot;A String&quot;, # If greater than zero, only the first `limit` rows are yielded. If `limit` is zero, the default is no limit. A limit can&#x27;t be specified if `partition_token` is set.
  &quot;lockHint&quot;: &quot;A String&quot;, # Optional. Lock Hint for the request, it can only be used with read-write transactions.
  &quot;orderBy&quot;: &quot;A String&quot;, # Optional. Order for the returned rows. By default, Spanner returns result rows in primary key order except for PartitionRead requests. For applications that don&#x27;t require rows to be returned in primary key (`ORDER_BY_PRIMARY_KEY`) order, setting `ORDER_BY_NO_ORDER` option allows Spanner to optimize row retrieval, resulting in lower latencies in certain cases (for example, bulk point lookups).
  &quot;partitionToken&quot;: &quot;A String&quot;, # If present, results are restricted to the specified partition previously created using `PartitionRead`. There must be an exact match for the values of fields common to this message and the PartitionReadRequest message used to create this partition_token.
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # If this request is resuming a previously interrupted read, `resume_token` should be copied from the last PartialResultSet yielded before the interruption. Doing this enables the new read to resume where the last read left off. The rest of the request parameters must exactly match the request that yielded this token.
  &quot;table&quot;: &quot;A String&quot;, # Required. The name of the table in the database to be read.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # The transaction to use. If none is provided, the default is a temporary read-only transaction with strong concurrency.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # Results from Read or ExecuteSql.
  &quot;metadata&quot;: { # Metadata about a ResultSet or PartialResultSet. # Metadata about the result set, such as row type information.
    &quot;rowType&quot;: { # `StructType` defines the fields of a STRUCT type. # Indicates the field names and types for the rows in the result set. For example, a SQL query like `&quot;SELECT UserId, UserName FROM Users&quot;` could return a `row_type` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
    &quot;transaction&quot;: { # A transaction. # If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.
      &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
      &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
        &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
        &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
      },
      &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
    },
    &quot;undeclaredParameters&quot;: { # `StructType` defines the fields of a STRUCT type. # A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like `&quot;SELECT * FROM Users where UserId = @userId and UserName = @userName &quot;` could return a `undeclared_parameters` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
  },
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction is on a multiplexed session. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;rows&quot;: [ # Each element in `rows` is a row whose format is defined by metadata.row_type. The ith element in each row matches the ith field in metadata.row_type. Elements are encoded based on type as described here.
    [
      &quot;&quot;,
    ],
  ],
  &quot;stats&quot;: { # Additional statistics about a ResultSet or PartialResultSet. # Query plan and execution statistics for the SQL statement that produced this result set. These can be requested by setting ExecuteSqlRequest.query_mode. DML statements always produce stats containing the number of rows modified, unless executed using the ExecuteSqlRequest.QueryMode.PLAN ExecuteSqlRequest.query_mode. Other fields might or might not be populated, based on the ExecuteSqlRequest.query_mode.
    &quot;queryPlan&quot;: { # Contains an ordered list of nodes appearing in the query plan. # QueryPlan for the query associated with this result.
      &quot;planNodes&quot;: [ # The nodes in the query plan. Plan nodes are returned in pre-order starting with the plan root. Each PlanNode&#x27;s `id` corresponds to its index in `plan_nodes`.
        { # Node information for nodes appearing in a QueryPlan.plan_nodes.
          &quot;childLinks&quot;: [ # List of child node `index`es and their relationship to this parent.
            { # Metadata associated with a parent-child relationship appearing in a PlanNode.
              &quot;childIndex&quot;: 42, # The node to which the link points.
              &quot;type&quot;: &quot;A String&quot;, # The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.
              &quot;variable&quot;: &quot;A String&quot;, # Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a `TableScan` operator that reads rows from a table will have child links to the `SCALAR` nodes representing the output variables created for each column that is read by the operator. The corresponding `variable` fields will be set to the variable names assigned to the columns.
            },
          ],
          &quot;displayName&quot;: &quot;A String&quot;, # The display name for the node.
          &quot;executionStats&quot;: { # The execution statistics associated with the node, contained in a group of key-value pairs. Only present if the plan was returned as a result of a profile query. For example, number of executions, number of rows/time per execution etc.
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;index&quot;: 42, # The `PlanNode`&#x27;s index in node list.
          &quot;kind&quot;: &quot;A String&quot;, # Used to determine the type of node. May be needed for visualizing different kinds of nodes differently. For example, If the node is a SCALAR node, it will have a condensed representation which can be used to directly embed a description of the node in its parent.
          &quot;metadata&quot;: { # Attributes relevant to the node contained in a group of key-value pairs. For example, a Parameter Reference node could have the following information in its metadata: { &quot;parameter_reference&quot;: &quot;param1&quot;, &quot;parameter_type&quot;: &quot;array&quot; }
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;shortRepresentation&quot;: { # Condensed representation of a node and its subtree. Only present for `SCALAR` PlanNode(s). # Condensed representation for SCALAR nodes.
            &quot;description&quot;: &quot;A String&quot;, # A string representation of the expression subtree rooted at this node.
            &quot;subqueries&quot;: { # A mapping of (subquery variable name) -&gt; (subquery node id) for cases where the `description` string of this node references a `SCALAR` subquery contained in the expression subtree rooted at this node. The referenced `SCALAR` subquery may not necessarily be a direct child of this node.
              &quot;a_key&quot;: 42,
            },
          },
        },
      ],
      &quot;queryAdvice&quot;: { # Output of query advisor analysis. # Optional. The advise/recommendations for a query. Currently this field will be serving index recommendations for a query.
        &quot;indexAdvice&quot;: [ # Optional. Index Recommendation for a query. This is an optional field and the recommendation will only be available when the recommendation guarantees significant improvement in query performance.
          { # Recommendation to add new indexes to run queries more efficiently.
            &quot;ddl&quot;: [ # Optional. DDL statements to add new indexes that will improve the query.
              &quot;A String&quot;,
            ],
            &quot;improvementFactor&quot;: 3.14, # Optional. Estimated latency improvement factor. For example if the query currently takes 500 ms to run and the estimated latency with new indexes is 100 ms this field will be 5.
          },
        ],
      },
    },
    &quot;queryStats&quot;: { # Aggregated statistics from the execution of the query. Only present when the query is profiled. For example, a query could return the statistics as follows: { &quot;rows_returned&quot;: &quot;3&quot;, &quot;elapsed_time&quot;: &quot;1.22 secs&quot;, &quot;cpu_time&quot;: &quot;1.19 secs&quot; }
      &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
    },
    &quot;rowCountExact&quot;: &quot;A String&quot;, # Standard DML returns an exact count of rows that were modified.
    &quot;rowCountLowerBound&quot;: &quot;A String&quot;, # Partitioned DML doesn&#x27;t offer exactly-once semantics, so it returns a lower bound of the rows modified.
  },
}</pre>
</div>

<div class="method">
    <code class="details" id="rollback">rollback(session, body=None, x__xgafv=None)</code>
  <pre>Rolls back a transaction, releasing any locks it holds. It&#x27;s a good idea to call this for any transaction that includes one or more Read or ExecuteSql requests and ultimately decides not to commit. `Rollback` returns `OK` if it successfully aborts the transaction, the transaction was already aborted, or the transaction isn&#x27;t found. `Rollback` never returns `ABORTED`.

Args:
  session: string, Required. The session in which the transaction to roll back is running. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for Rollback.
  &quot;transactionId&quot;: &quot;A String&quot;, # Required. The transaction to roll back.
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # A generic empty message that you can re-use to avoid defining duplicated empty messages in your APIs. A typical example is to use it as the request or the response type of an API method. For instance: service Foo { rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty); }
}</pre>
</div>

<div class="method">
    <code class="details" id="streamingRead">streamingRead(session, body=None, x__xgafv=None)</code>
  <pre>Like Read, except returns the result set as a stream. Unlike Read, there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.

Args:
  session: string, Required. The session in which the read should be performed. (required)
  body: object, The request body.
    The object takes the form of:

{ # The request for Read and StreamingRead.
  &quot;columns&quot;: [ # Required. The columns of table to be returned for each row matching this request.
    &quot;A String&quot;,
  ],
  &quot;dataBoostEnabled&quot;: True or False, # If this is for a partitioned read and this field is set to `true`, the request is executed with Spanner Data Boost independent compute resources. If the field is set to `true` but the request doesn&#x27;t set `partition_token`, the API returns an `INVALID_ARGUMENT` error.
  &quot;directedReadOptions&quot;: { # The `DirectedReadOptions` can be used to indicate which replicas or regions should be used for non-transactional reads or queries. `DirectedReadOptions` can only be specified for a read-only transaction, otherwise the API returns an `INVALID_ARGUMENT` error. # Directed read options for this request.
    &quot;excludeReplicas&quot;: { # An ExcludeReplicas contains a repeated set of ReplicaSelection that should be excluded from serving requests. # `Exclude_replicas` indicates that specified replicas should be excluded from serving requests. Spanner doesn&#x27;t route requests to the replicas in this list.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
    &quot;includeReplicas&quot;: { # An `IncludeReplicas` contains a repeated set of `ReplicaSelection` which indicates the order in which replicas should be considered. # `Include_replicas` indicates the order of replicas (as they appear in this list) to process the request. If `auto_failover_disabled` is set to `true` and all replicas are exhausted without finding a healthy replica, Spanner waits for a replica in the list to become available, requests might fail due to `DEADLINE_EXCEEDED` errors.
      &quot;autoFailoverDisabled&quot;: True or False, # If `true`, Spanner doesn&#x27;t route requests to a replica outside the &lt;`include_replicas` list when all of the specified replicas are unavailable or unhealthy. Default value is `false`.
      &quot;replicaSelections&quot;: [ # The directed read replica selector.
        { # The directed read replica selector. Callers must provide one or more of the following fields for replica selection: * `location` - The location must be one of the regions within the multi-region configuration of your database. * `type` - The type of the replica. Some examples of using replica_selectors are: * `location:us-east1` --&gt; The &quot;us-east1&quot; replica(s) of any available type is used to process the request. * `type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in the nearest available location are used to process the request. * `location:us-east1 type:READ_ONLY` --&gt; The &quot;READ_ONLY&quot; type replica(s) in location &quot;us-east1&quot; is used to process the request.
          &quot;location&quot;: &quot;A String&quot;, # The location or region of the serving requests, for example, &quot;us-east1&quot;.
          &quot;type&quot;: &quot;A String&quot;, # The type of replica.
        },
      ],
    },
  },
  &quot;index&quot;: &quot;A String&quot;, # If non-empty, the name of an index on table. This index is used instead of the table primary key when interpreting key_set and sorting result rows. See key_set for further information.
  &quot;keySet&quot;: { # `KeySet` defines a collection of Cloud Spanner keys and/or key ranges. All the keys are expected to be in the same table or index. The keys need not be sorted in any particular way. If the same key is specified multiple times in the set (for example if two ranges, two keys, or a key and a range overlap), Cloud Spanner behaves as if the key were only specified once. # Required. `key_set` identifies the rows to be yielded. `key_set` names the primary keys of the rows in table to be yielded, unless index is present. If index is present, then key_set instead names index keys in index. If the partition_token field is empty, rows are yielded in table primary key order (if index is empty) or index key order (if index is non-empty). If the partition_token field isn&#x27;t empty, rows are yielded in an unspecified order. It isn&#x27;t an error for the `key_set` to name rows that don&#x27;t exist in the database. Read yields nothing for nonexistent rows.
    &quot;all&quot;: True or False, # For convenience `all` can be set to `true` to indicate that this `KeySet` matches all keys in the table or index. Note that any keys specified in `keys` or `ranges` are only yielded once.
    &quot;keys&quot;: [ # A list of specific keys. Entries in `keys` should have exactly as many elements as there are columns in the primary or index key with which this `KeySet` is used. Individual key values are encoded as described here.
      [
        &quot;&quot;,
      ],
    ],
    &quot;ranges&quot;: [ # A list of key ranges. See KeyRange for more information about key range specifications.
      { # KeyRange represents a range of rows in a table or index. A range has a start key and an end key. These keys can be open or closed, indicating if the range includes rows with that key. Keys are represented by lists, where the ith value in the list corresponds to the ith component of the table or index primary key. Individual values are encoded as described here. For example, consider the following table definition: CREATE TABLE UserEvents ( UserName STRING(MAX), EventDate STRING(10) ) PRIMARY KEY(UserName, EventDate); The following keys name rows in this table: &quot;Bob&quot;, &quot;2014-09-23&quot; Since the `UserEvents` table&#x27;s `PRIMARY KEY` clause names two columns, each `UserEvents` key has two elements; the first is the `UserName`, and the second is the `EventDate`. Key ranges with multiple components are interpreted lexicographically by component using the table or index key&#x27;s declared sort order. For example, the following range returns all events for user `&quot;Bob&quot;` that occurred in the year 2015: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2015-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;, &quot;2015-12-31&quot;] Start and end keys can omit trailing key components. This affects the inclusion and exclusion of rows that exactly match the provided key components: if the key is closed, then rows that exactly match the provided components are included; if the key is open, then rows that exactly match are not included. For example, the following range includes all events for `&quot;Bob&quot;` that occurred during and after the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] The next example retrieves all events for `&quot;Bob&quot;`: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_closed&quot;: [&quot;Bob&quot;] To retrieve events before the year 2000: &quot;start_closed&quot;: [&quot;Bob&quot;] &quot;end_open&quot;: [&quot;Bob&quot;, &quot;2000-01-01&quot;] The following range includes all rows in the table: &quot;start_closed&quot;: [] &quot;end_closed&quot;: [] This range returns all users whose `UserName` begins with any character from A to C: &quot;start_closed&quot;: [&quot;A&quot;] &quot;end_open&quot;: [&quot;D&quot;] This range returns all users whose `UserName` begins with B: &quot;start_closed&quot;: [&quot;B&quot;] &quot;end_open&quot;: [&quot;C&quot;] Key ranges honor column sort order. For example, suppose a table is defined as follows: CREATE TABLE DescendingSortedTable { Key INT64, ... ) PRIMARY KEY(Key DESC); The following range retrieves all rows with key values between 1 and 100 inclusive: &quot;start_closed&quot;: [&quot;100&quot;] &quot;end_closed&quot;: [&quot;1&quot;] Note that 100 is passed as the start, and 1 is passed as the end, because `Key` is a descending column in the schema.
        &quot;endClosed&quot;: [ # If the end is closed, then the range includes all rows whose first `len(end_closed)` key columns exactly match `end_closed`.
          &quot;&quot;,
        ],
        &quot;endOpen&quot;: [ # If the end is open, then the range excludes rows whose first `len(end_open)` key columns exactly match `end_open`.
          &quot;&quot;,
        ],
        &quot;startClosed&quot;: [ # If the start is closed, then the range includes all rows whose first `len(start_closed)` key columns exactly match `start_closed`.
          &quot;&quot;,
        ],
        &quot;startOpen&quot;: [ # If the start is open, then the range excludes rows whose first `len(start_open)` key columns exactly match `start_open`.
          &quot;&quot;,
        ],
      },
    ],
  },
  &quot;limit&quot;: &quot;A String&quot;, # If greater than zero, only the first `limit` rows are yielded. If `limit` is zero, the default is no limit. A limit can&#x27;t be specified if `partition_token` is set.
  &quot;lockHint&quot;: &quot;A String&quot;, # Optional. Lock Hint for the request, it can only be used with read-write transactions.
  &quot;orderBy&quot;: &quot;A String&quot;, # Optional. Order for the returned rows. By default, Spanner returns result rows in primary key order except for PartitionRead requests. For applications that don&#x27;t require rows to be returned in primary key (`ORDER_BY_PRIMARY_KEY`) order, setting `ORDER_BY_NO_ORDER` option allows Spanner to optimize row retrieval, resulting in lower latencies in certain cases (for example, bulk point lookups).
  &quot;partitionToken&quot;: &quot;A String&quot;, # If present, results are restricted to the specified partition previously created using `PartitionRead`. There must be an exact match for the values of fields common to this message and the PartitionReadRequest message used to create this partition_token.
  &quot;requestOptions&quot;: { # Common request options for various APIs. # Common options for this request.
    &quot;priority&quot;: &quot;A String&quot;, # Priority for the request.
    &quot;requestTag&quot;: &quot;A String&quot;, # A per-request tag which can be applied to queries or reads, used for statistics collection. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. This field is ignored for requests where it&#x27;s not applicable (for example, `CommitRequest`). Legal characters for `request_tag` values are all printable characters (ASCII 32 - 126) and the length of a request_tag is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
    &quot;transactionTag&quot;: &quot;A String&quot;, # A tag used for statistics collection about this transaction. Both `request_tag` and `transaction_tag` can be specified for a read or query that belongs to a transaction. The value of transaction_tag should be the same for all requests belonging to the same transaction. If this request doesn&#x27;t belong to any transaction, `transaction_tag` is ignored. Legal characters for `transaction_tag` values are all printable characters (ASCII 32 - 126) and the length of a `transaction_tag` is limited to 50 characters. Values that exceed this limit are truncated. Any leading underscore (_) characters are removed from the string.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # If this request is resuming a previously interrupted read, `resume_token` should be copied from the last PartialResultSet yielded before the interruption. Doing this enables the new read to resume where the last read left off. The rest of the request parameters must exactly match the request that yielded this token.
  &quot;table&quot;: &quot;A String&quot;, # Required. The name of the table in the database to be read.
  &quot;transaction&quot;: { # This message is used to select the transaction in which a Read or ExecuteSql call runs. See TransactionOptions for more information about transactions. # The transaction to use. If none is provided, the default is a temporary read-only transaction with strong concurrency.
    &quot;begin&quot;: { # Options to use for transactions. # Begin a new transaction and execute this read or SQL query in it. The transaction ID of the new transaction is returned in ResultSetMetadata.transaction, which is a Transaction.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
    &quot;id&quot;: &quot;A String&quot;, # Execute the read or SQL query in a previously-started transaction.
    &quot;singleUse&quot;: { # Options to use for transactions. # Execute the read or SQL query in a temporary transaction. This is the most efficient way to execute a transaction that consists of a single SQL query.
      &quot;excludeTxnFromChangeStreams&quot;: True or False, # When `exclude_txn_from_change_streams` is set to `true`, it prevents read or write transactions from being tracked in change streams. * If the DDL option `allow_txn_exclusion` is set to `true`, then the updates made within this transaction aren&#x27;t recorded in the change stream. * If you don&#x27;t set the DDL option `allow_txn_exclusion` or if it&#x27;s set to `false`, then the updates made within this transaction are recorded in the change stream. When `exclude_txn_from_change_streams` is set to `false` or not set, modifications from this transaction are recorded in all change streams that are tracking columns modified by these transactions. The `exclude_txn_from_change_streams` option can only be specified for read-write or partitioned DML transactions, otherwise the API returns an `INVALID_ARGUMENT` error.
      &quot;isolationLevel&quot;: &quot;A String&quot;, # Isolation level for the transaction.
      &quot;partitionedDml&quot;: { # Message type to initiate a Partitioned DML transaction. # Partitioned DML transaction. Authorization to begin a Partitioned DML transaction requires `spanner.databases.beginPartitionedDmlTransaction` permission on the `session` resource.
      },
      &quot;readOnly&quot;: { # Message type to initiate a read-only transaction. # Transaction does not write. Authorization to begin a read-only transaction requires `spanner.databases.beginReadOnlyTransaction` permission on the `session` resource.
        &quot;exactStaleness&quot;: &quot;A String&quot;, # Executes all reads at a timestamp that is `exact_staleness` old. The timestamp is chosen soon after the read is started. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading at nearby replicas without the distributed timestamp negotiation overhead of `max_staleness`.
        &quot;maxStaleness&quot;: &quot;A String&quot;, # Read data at a timestamp &gt;= `NOW - max_staleness` seconds. Guarantees that all writes that have committed more than the specified number of seconds ago are visible. Because Cloud Spanner chooses the exact timestamp, this mode works even if the client&#x27;s local clock is substantially skewed from Cloud Spanner commit timestamps. Useful for reading the freshest data available at a nearby replica, while bounding the possible staleness if the local replica has fallen behind. Note that this option can only be used in single-use transactions.
        &quot;minReadTimestamp&quot;: &quot;A String&quot;, # Executes all reads at a timestamp &gt;= `min_read_timestamp`. This is useful for requesting fresher data than some previous read, or data that is fresh enough to observe the effects of some previously committed transaction whose timestamp is known. Note that this option can only be used in single-use transactions. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;readTimestamp&quot;: &quot;A String&quot;, # Executes all reads at the given timestamp. Unlike other modes, reads at a specific timestamp are repeatable; the same read at the same timestamp always returns the same data. If the timestamp is in the future, the read is blocked until the specified timestamp, modulo the read&#x27;s deadline. Useful for large scale consistent reads such as mapreduces, or for coordinating many reads against a consistent snapshot of the data. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
        &quot;returnReadTimestamp&quot;: True or False, # If true, the Cloud Spanner-selected read timestamp is included in the Transaction message that describes the transaction.
        &quot;strong&quot;: True or False, # Read at a timestamp where all previously committed transactions are visible.
      },
      &quot;readWrite&quot;: { # Message type to initiate a read-write transaction. Currently this transaction type has no options. # Transaction may write. Authorization to begin a read-write transaction requires `spanner.databases.beginOrRollbackReadWriteTransaction` permission on the `session` resource.
        &quot;multiplexedSessionPreviousTransactionId&quot;: &quot;A String&quot;, # Optional. Clients should pass the transaction ID of the previous transaction attempt that was aborted if this transaction is being executed on a multiplexed session.
        &quot;readLockMode&quot;: &quot;A String&quot;, # Read lock mode for the transaction.
      },
    },
  },
}

  x__xgafv: string, V1 error format.
    Allowed values
      1 - v1 error format
      2 - v2 error format

Returns:
  An object of the form:

    { # Partial results from a streaming read or SQL query. Streaming reads and SQL queries better tolerate large result sets, large rows, and large values, but are a little trickier to consume.
  &quot;chunkedValue&quot;: True or False, # If true, then the final value in values is chunked, and must be combined with more values from subsequent `PartialResultSet`s to obtain a complete field value.
  &quot;last&quot;: True or False, # Optional. Indicates whether this is the last `PartialResultSet` in the stream. The server might optionally set this field. Clients shouldn&#x27;t rely on this field being set in all cases.
  &quot;metadata&quot;: { # Metadata about a ResultSet or PartialResultSet. # Metadata about the result set, such as row type information. Only present in the first response.
    &quot;rowType&quot;: { # `StructType` defines the fields of a STRUCT type. # Indicates the field names and types for the rows in the result set. For example, a SQL query like `&quot;SELECT UserId, UserName FROM Users&quot;` could return a `row_type` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
    &quot;transaction&quot;: { # A transaction. # If the read or SQL query began a transaction as a side-effect, the information about the new transaction is yielded here.
      &quot;id&quot;: &quot;A String&quot;, # `id` may be used to identify the transaction in subsequent Read, ExecuteSql, Commit, or Rollback calls. Single-use read-only transactions do not have IDs, because single-use transactions do not support multiple requests.
      &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # A precommit token is included in the response of a BeginTransaction request if the read-write transaction is on a multiplexed session and a mutation_key was specified in the BeginTransaction. The precommit token with the highest sequence number from this transaction attempt should be passed to the Commit request for this transaction.
        &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
        &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
      },
      &quot;readTimestamp&quot;: &quot;A String&quot;, # For snapshot read-only transactions, the read timestamp chosen for the transaction. Not returned by default: see TransactionOptions.ReadOnly.return_read_timestamp. A timestamp in RFC3339 UTC \&quot;Zulu\&quot; format, accurate to nanoseconds. Example: `&quot;2014-10-02T15:01:23.045123456Z&quot;`.
    },
    &quot;undeclaredParameters&quot;: { # `StructType` defines the fields of a STRUCT type. # A SQL query can be parameterized. In PLAN mode, these parameters can be undeclared. This indicates the field names and types for those undeclared parameters in the SQL query. For example, a SQL query like `&quot;SELECT * FROM Users where UserId = @userId and UserName = @userName &quot;` could return a `undeclared_parameters` value like: &quot;fields&quot;: [ { &quot;name&quot;: &quot;UserId&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;INT64&quot; } }, { &quot;name&quot;: &quot;UserName&quot;, &quot;type&quot;: { &quot;code&quot;: &quot;STRING&quot; } }, ]
      &quot;fields&quot;: [ # The list of fields that make up this struct. Order is significant, because values of this struct type are represented as lists, where the order of field values matches the order of fields in the StructType. In turn, the order of fields matches the order of columns in a read request, or the order of fields in the `SELECT` clause of a query.
        { # Message representing a single field of a struct.
          &quot;name&quot;: &quot;A String&quot;, # The name of the field. For reads, this is the column name. For SQL queries, it is the column alias (e.g., `&quot;Word&quot;` in the query `&quot;SELECT &#x27;hello&#x27; AS Word&quot;`), or the column name (e.g., `&quot;ColName&quot;` in the query `&quot;SELECT ColName FROM Table&quot;`). Some columns might have an empty name (e.g., `&quot;SELECT UPPER(ColName)&quot;`). Note that a query result can contain multiple fields with the same name.
          &quot;type&quot;: # Object with schema name: Type # The type of the field.
        },
      ],
    },
  },
  &quot;precommitToken&quot;: { # When a read-write transaction is executed on a multiplexed session, this precommit token is sent back to the client as a part of the Transaction message in the BeginTransaction response and also as a part of the ResultSet and PartialResultSet responses. # Optional. A precommit token is included if the read-write transaction has multiplexed sessions enabled. Pass the precommit token with the highest sequence number from this transaction attempt to the Commit request for this transaction.
    &quot;precommitToken&quot;: &quot;A String&quot;, # Opaque precommit token.
    &quot;seqNum&quot;: 42, # An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.
  },
  &quot;resumeToken&quot;: &quot;A String&quot;, # Streaming calls might be interrupted for a variety of reasons, such as TCP connection loss. If this occurs, the stream of results can be resumed by re-sending the original request and including `resume_token`. Note that executing any other transaction in the same session invalidates the token.
  &quot;stats&quot;: { # Additional statistics about a ResultSet or PartialResultSet. # Query plan and execution statistics for the statement that produced this streaming result set. These can be requested by setting ExecuteSqlRequest.query_mode and are sent only once with the last response in the stream. This field is also present in the last response for DML statements.
    &quot;queryPlan&quot;: { # Contains an ordered list of nodes appearing in the query plan. # QueryPlan for the query associated with this result.
      &quot;planNodes&quot;: [ # The nodes in the query plan. Plan nodes are returned in pre-order starting with the plan root. Each PlanNode&#x27;s `id` corresponds to its index in `plan_nodes`.
        { # Node information for nodes appearing in a QueryPlan.plan_nodes.
          &quot;childLinks&quot;: [ # List of child node `index`es and their relationship to this parent.
            { # Metadata associated with a parent-child relationship appearing in a PlanNode.
              &quot;childIndex&quot;: 42, # The node to which the link points.
              &quot;type&quot;: &quot;A String&quot;, # The type of the link. For example, in Hash Joins this could be used to distinguish between the build child and the probe child, or in the case of the child being an output variable, to represent the tag associated with the output variable.
              &quot;variable&quot;: &quot;A String&quot;, # Only present if the child node is SCALAR and corresponds to an output variable of the parent node. The field carries the name of the output variable. For example, a `TableScan` operator that reads rows from a table will have child links to the `SCALAR` nodes representing the output variables created for each column that is read by the operator. The corresponding `variable` fields will be set to the variable names assigned to the columns.
            },
          ],
          &quot;displayName&quot;: &quot;A String&quot;, # The display name for the node.
          &quot;executionStats&quot;: { # The execution statistics associated with the node, contained in a group of key-value pairs. Only present if the plan was returned as a result of a profile query. For example, number of executions, number of rows/time per execution etc.
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;index&quot;: 42, # The `PlanNode`&#x27;s index in node list.
          &quot;kind&quot;: &quot;A String&quot;, # Used to determine the type of node. May be needed for visualizing different kinds of nodes differently. For example, If the node is a SCALAR node, it will have a condensed representation which can be used to directly embed a description of the node in its parent.
          &quot;metadata&quot;: { # Attributes relevant to the node contained in a group of key-value pairs. For example, a Parameter Reference node could have the following information in its metadata: { &quot;parameter_reference&quot;: &quot;param1&quot;, &quot;parameter_type&quot;: &quot;array&quot; }
            &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
          },
          &quot;shortRepresentation&quot;: { # Condensed representation of a node and its subtree. Only present for `SCALAR` PlanNode(s). # Condensed representation for SCALAR nodes.
            &quot;description&quot;: &quot;A String&quot;, # A string representation of the expression subtree rooted at this node.
            &quot;subqueries&quot;: { # A mapping of (subquery variable name) -&gt; (subquery node id) for cases where the `description` string of this node references a `SCALAR` subquery contained in the expression subtree rooted at this node. The referenced `SCALAR` subquery may not necessarily be a direct child of this node.
              &quot;a_key&quot;: 42,
            },
          },
        },
      ],
      &quot;queryAdvice&quot;: { # Output of query advisor analysis. # Optional. The advise/recommendations for a query. Currently this field will be serving index recommendations for a query.
        &quot;indexAdvice&quot;: [ # Optional. Index Recommendation for a query. This is an optional field and the recommendation will only be available when the recommendation guarantees significant improvement in query performance.
          { # Recommendation to add new indexes to run queries more efficiently.
            &quot;ddl&quot;: [ # Optional. DDL statements to add new indexes that will improve the query.
              &quot;A String&quot;,
            ],
            &quot;improvementFactor&quot;: 3.14, # Optional. Estimated latency improvement factor. For example if the query currently takes 500 ms to run and the estimated latency with new indexes is 100 ms this field will be 5.
          },
        ],
      },
    },
    &quot;queryStats&quot;: { # Aggregated statistics from the execution of the query. Only present when the query is profiled. For example, a query could return the statistics as follows: { &quot;rows_returned&quot;: &quot;3&quot;, &quot;elapsed_time&quot;: &quot;1.22 secs&quot;, &quot;cpu_time&quot;: &quot;1.19 secs&quot; }
      &quot;a_key&quot;: &quot;&quot;, # Properties of the object.
    },
    &quot;rowCountExact&quot;: &quot;A String&quot;, # Standard DML returns an exact count of rows that were modified.
    &quot;rowCountLowerBound&quot;: &quot;A String&quot;, # Partitioned DML doesn&#x27;t offer exactly-once semantics, so it returns a lower bound of the rows modified.
  },
  &quot;values&quot;: [ # A streamed result set consists of a stream of values, which might be split into many `PartialResultSet` messages to accommodate large rows and/or large values. Every N complete values defines a row, where N is equal to the number of entries in metadata.row_type.fields. Most values are encoded based on type as described here. It&#x27;s possible that the last value in values is &quot;chunked&quot;, meaning that the rest of the value is sent in subsequent `PartialResultSet`(s). This is denoted by the chunked_value field. Two or more chunked values can be merged to form a complete value as follows: * `bool/number/null`: can&#x27;t be chunked * `string`: concatenate the strings * `list`: concatenate the lists. If the last element in a list is a `string`, `list`, or `object`, merge it with the first element in the next list by applying these rules recursively. * `object`: concatenate the (field name, field value) pairs. If a field name is duplicated, then apply these rules recursively to merge the field values. Some examples of merging: Strings are concatenated. &quot;foo&quot;, &quot;bar&quot; =&gt; &quot;foobar&quot; Lists of non-strings are concatenated. [2, 3], [4] =&gt; [2, 3, 4] Lists are concatenated, but the last and first elements are merged because they are strings. [&quot;a&quot;, &quot;b&quot;], [&quot;c&quot;, &quot;d&quot;] =&gt; [&quot;a&quot;, &quot;bc&quot;, &quot;d&quot;] Lists are concatenated, but the last and first elements are merged because they are lists. Recursively, the last and first elements of the inner lists are merged because they are strings. [&quot;a&quot;, [&quot;b&quot;, &quot;c&quot;]], [[&quot;d&quot;], &quot;e&quot;] =&gt; [&quot;a&quot;, [&quot;b&quot;, &quot;cd&quot;], &quot;e&quot;] Non-overlapping object fields are combined. {&quot;a&quot;: &quot;1&quot;}, {&quot;b&quot;: &quot;2&quot;} =&gt; {&quot;a&quot;: &quot;1&quot;, &quot;b&quot;: 2&quot;} Overlapping object fields are merged. {&quot;a&quot;: &quot;1&quot;}, {&quot;a&quot;: &quot;2&quot;} =&gt; {&quot;a&quot;: &quot;12&quot;} Examples of merging objects containing lists of strings. {&quot;a&quot;: [&quot;1&quot;]}, {&quot;a&quot;: [&quot;2&quot;]} =&gt; {&quot;a&quot;: [&quot;12&quot;]} For a more complete example, suppose a streaming SQL query is yielding a result set whose rows contain a single string field. The following `PartialResultSet`s might be yielded: { &quot;metadata&quot;: { ... } &quot;values&quot;: [&quot;Hello&quot;, &quot;W&quot;] &quot;chunked_value&quot;: true &quot;resume_token&quot;: &quot;Af65...&quot; } { &quot;values&quot;: [&quot;orl&quot;] &quot;chunked_value&quot;: true } { &quot;values&quot;: [&quot;d&quot;] &quot;resume_token&quot;: &quot;Zx1B...&quot; } This sequence of `PartialResultSet`s encodes two rows, one containing the field value `&quot;Hello&quot;`, and a second containing the field value `&quot;World&quot; = &quot;W&quot; + &quot;orl&quot; + &quot;d&quot;`. Not all `PartialResultSet`s contain a `resume_token`. Execution can only be resumed from a previously yielded `resume_token`. For the above sequence of `PartialResultSet`s, resuming the query with `&quot;resume_token&quot;: &quot;Af65...&quot;` yields results from the `PartialResultSet` with value &quot;orl&quot;.
    &quot;&quot;,
  ],
}</pre>
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